ASP.NET Code Book (Learn asp.net from example)

How to submit(Post) a webfrom from python/IronPython

2012-01-14T06:14:00.000-08:00

In this post,I am going to show you how to post data from python to a webfrom from python.

import urllib.parse
import urllib.request
url='http://www.dijksterhuis.org/test/post.php'
values={'keyword':'Void',
        'data':'aspdotnetcodebook'
        }
data=urllib.parse.urlencode(values)
binary_data = data.encode('utf-8')
req=urllib.request.Request(url,binary_data)
response=urllib.request.urlopen(req)
the_page=response.read()
print (the_page)

How to create self signed certificate using makecert

2011-12-11T02:40:00.000-08:00

In this post,I will show you how to create self signed certificate for wcf application.For this,I will used the utility makecert.MakeCert.exe allows you to (for test/dev purposes) generate both a trusted root certificate and a certificate signed by that trusted root certificate for encryption purposes (also for signature purposes.

Open visual studio command prompt (Admin mode) and type following command

C:\cert>makecert -pe -n "CN=RootCA" -ss My -sr LocalMachine -a sha1 -sky signatu re -r "RootCA.cer"

-pe Marks the generated private key as exportable. This allows the private key to be included in the certificate.
-n Specifies the subject's certificate name. This name must conform to the X.500 standard. The simplest method is to specify the name in double quotes, preceded by CN=; for example, "CN=myName".
-ss Specifies the subject's certificate store name that stores the output certificate.
-sr Specifies the subject's certificate store location. Location can be either currentuser (the default), or localmachine.
-a Specifies the signature algorithm. Must be either md5 (the default) or sha1.
-sky Specifies the subject's key type, which must be signature, exchange, or an integer that represents a provider type. By default, you can pass 1for an exchange key and 2 for a signature key.
-r Creates a self-signed certificate.

Above command will create a certificate named RootCA.cer in the cert directory ,and also placed this certificate into Person folder.
After executing the above command do the following steps

Start/Run/MMC
File/Add-Remove Snap-In
Click Add
Select Certificates and click Add
Select Computer Account and hit Next
Select Local Computer
Click Close
Click OK

Go back to the certificates snap-in, right-click the "RootCA" certificate and copy it to the "Trusted Root Certification Authorities" node. Once done, if you expand this node, and then select certificates your newly created root cert should be present.

Now,It's time to create the server certificate.Type the following command and press enter

C:\cert>makecert -pe -n "CN=santosh-pc" -ss My -sr LocalMachine -sky exchange -a
sha1 -in "RootCA" -is My -ir LocalMachine -sy 12 santosh-pc.cer

How to validate asp.net form using Jquery

2011-10-20T11:38:00.000-07:00

In this post I will show you how to validate asp.net form using jqery. Create a new website,add a new js file ,and add following code inside it

function validateForm(e) {
    var formIsValid = true;
    // check that a valid email address has been entered
    var emailRegExp = /[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}/;
    if (!emailRegExp.test(String($("#txtEmail").val()).toUpperCase())) {
        addError("txtEmail", "Please enter a valid email address.");
        formIsValid = false;
    } else {
        removeError("txtEmail");
    }

    // check that first name has one or more characters
    if ($("#txtFirstName").val() == '') {
        addError("txtFirstName", "This field is required.");
        formIsValid = false;
    } else {
        removeError("txtFirstName");
    }
    // check that last name has one or more characters
    if ($("#txtLastName").val() == '') {
        addError("txtLastName", "This field is required.");
        formIsValid = false;
    } else {
        removeError("txtLastName");
    }

    // check that a valid phone number is entered
    var phoneRegExp = /^\(?[1-9]\d{2}\)?\s?\-?\.?\d{3}\s?\-?\.?\d{4}$/;
    if (!phoneRegExp.test($("#txtPhone").val())) {
        addError("txtPhone", "Valid phone number required.");
        formIsValid = false;
    } else {
        removeError("txtPhone");
    }

    if (!formIsValid) {
        e.preventDefault();
    }
}

function addError(id, msg) {
    if ($("#" + id).parent().find("label[class=error]").attr("generated") == "true") {
        $("#" + id).parent().find("label[class=error]").css("display", "block");
    } else {
        $("#" + id).parent().append('<label for="' + id + '" generated="true" class="error">' + msg + '</label>').css("display", "block");
    }
}
function removeError(id) {
    $("#" + id).parent().find("label[class=error]").css("display", "none");
}

Add a new page.Then add reference of jquery and above js file

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default2.aspx.cs" Inherits="Default2" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <script type="text/javascript" src="Scripts/jquery-1.4.1.js"></script>
    <script type="text/javascript" src="Scripts/Validation.js"></script>
    <title></title>
    <script type="text/javascript">
        $(document).ready(function () {
            $(".submitForm").click(function (e) {
                validateForm(e);
            });
        });
    </script>
    <style type="text/css">
    .error{color:Red;}
    </style>
</head>
<body>
    <form id="form1" runat="server">
    <table class="style1">
        <tr>
            <td>
                FirstName
            </td>
            <td>
                <asp:TextBox ID="txtFirstName"  runat="server"></asp:TextBox>
            </td>
        </tr>
        <tr>
            <td>
                LastName
            </td>
            <td>
                <asp:TextBox ID="txtLastName"  runat="server"></asp:TextBox>
            </td>
        </tr>
        <tr>
            <td>
                Phone Number
            </td>
            <td>
                <asp:TextBox ID="txtPhone"  runat="server"></asp:TextBox>
            </td>
        </tr>
        <tr>
            <td>
                Email
            </td>
            <td>
                <asp:TextBox ID="txtEmail"  runat="server"></asp:TextBox>
            </td>
        </tr>
    </table>
    <div>
        <input type="button" id="btnSubmit" class="submitForm" value="Submit" />
    </div>
    </form>
</body>
</html>

How to enable/disable dropdownlist through a checkbox selection

2011-10-09T05:10:00.000-07:00

In this post,I will show you how to enable/disable dropdownlist control through checkbox selection in asp.net.

Create a new website
Right click on the website,add a new webpage,and add following code into it

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default2.aspx.cs" Inherits="Default2" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <script src="Scripts/jquery-1.4.1.js" type="text/javascript"></script>
    <script type="text/javascript">
        $(document).ready(function () {
            $("#chkEnable").click(function () {
                if (this.checked)
                    $('#ddlList').attr('disabled', 'disabled');
                else
                    $('#ddlList').removeAttr('disabled');
            });
        });
    </script>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:CheckBox ID="chkEnable" runat="server" Text="Enable/Disable" /><br />
        <asp:DropDownList ID="ddlList" runat="server">
            <asp:ListItem Text="Select" Value="-1">
            </asp:ListItem>
            <asp:ListItem Text="Option1" Value="1" />
            <asp:ListItem Text="Option2" Value="2" />
            <asp:ListItem Text="Option3" Value="3" />
        </asp:DropDownList>
    </div>
    </form>
</body>
</html>

{Click here for live demo}

How to change default binding in WCF 4.0

2011-10-08T13:21:00.000-07:00

With WCF 3.x, if you try to host a service without any configured endpoints, the ServiceHost instance will throw an exception informing you that you need to configure at least one endpoint. With WCF 4, this is no longer the case because the runtime automatically adds one or more “default endpoints” for you, thereby making the service usable without any configuration.
If you want to change default binding then open web.config and do following entry in <system.serviceModel>

<system.serviceModel>

<protocolMapping>

<add binding="basicHttpBinding" scheme="Http"/>

</protocolMapping>

</system.serviceModel>

How to upload/Download file from wcf service

2011-10-08T12:09:00.000-07:00

In this post,I will show you how to stream (upload and download) data through wcfservice.



Create a new website 
Right click on the website and add new wcf service named FileStream.svc
Open the IFileStream.cs and add following code


using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.Text;
using System.IO;
[ServiceContract]
public interface IFileStream
{
    [OperationContract]
    string Upload(Stream inputStream);
    [OperationContract]
    Stream Download(string fileId);
    [OperationContract]
    string[] GetAvailableFiles();
}





Open FileStream.cs file and add following code inside it




using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.Text;
using System.IO;
using System.Web;



// NOTE: You can use the "Rename" command on the "Refactor" menu to change the class name "Service" in code, svc and config file together.
public class FileStream : IFileStream
{
    private const string FILEPATH = @"C:\temp\download";

    private string GetDirectoryPath()
    {
        return FILEPATH;
    }
    public string Upload(System.IO.Stream inputStream)
    {
        string fileID = string.Format(@"{0}\{1}.txt", GetDirectoryPath(), Guid.NewGuid().ToString());
        StreamReader reader = new StreamReader(inputStream);
        string contents = reader.ReadToEnd();
        File.WriteAllText(fileID, contents);
        return fileID;
    }

    public System.IO.Stream Download(string fileId)
    {
        MemoryStream stream = new MemoryStream();
        byte[] buffer = File.ReadAllBytes(fileId);
        stream.Write(buffer, 0, buffer.Length);
        stream.Position = 0;
        return stream;
    }
    public string[] GetAvailableFiles()
    {
        return new DirectoryInfo(GetDirectoryPath()).GetFiles().Select(x => x.FullName).ToArray();
    }
}





Now,It's time to configure the service.There are two way to configure the service.First through the code ,and second through the config file.I will followlatter approach.Open web.config and go to  section and add following code 




<?xml version="1.0"?>
<configuration>
  <system.web>
    <compilation debug="true" targetFramework="4.0"/>
  </system.web>
  <system.serviceModel>
    <services>
      <service behaviorConfiguration="streamServiceBehaviour" name="FileStream">
        <endpoint address="" binding="basicHttpBinding" contract="IFileStream" bindingConfiguration="streamBindingConfig"/>
        <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange"/>
      </service>
    </services>
    <behaviors>
      <serviceBehaviors>
        <behavior name="streamServiceBehaviour">
          <serviceDebug includeExceptionDetailInFaults="true"/>
          <serviceMetadata httpGetEnabled="true"/>
        </behavior>
      </serviceBehaviors>
    </behaviors>
    <bindings>
      <basicHttpBinding>
        <binding name="streamBindingConfig" transferMode="Streamed">
        </binding>
      </basicHttpBinding>
    </bindings>
  </system.serviceModel>
</configuration>







In the above configuration,I have used basicHttpBinding and transferMode is Streamed..



Let's consume the service.Right click on the project and add new page and add following code into it






<%@ Page Language="C#" AutoEventWireup="true" CodeFile="ServiceExample.aspx.cs" Inherits="ServiceExample" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:FileUpload ID="FileUpload1" runat="server" />
        <asp:Button ID="btnUpload" runat="server" OnClick="btnUpload_Click" Text="Upload" />
    </div>
    <asp:Button ID="btnDownload" runat="server" onclick="btnDownload_Click" 
        Text="Download" />
    <asp:TextBox ID="TextBox1" runat="server" Height="235px" Width="377px"></asp:TextBox>
    </form>
</body>
</html>




using System;

using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.IO;

public partial class ServiceExample : System.Web.UI.Page
{
    StreamService.FileStreamClient client = new StreamService.FileStreamClient();
    string fileId = string.Empty;
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void btnUpload_Click(object sender, EventArgs e)
    {
 
     fileId=client.Upload(new MemoryStream(FileUpload1.FileBytes));
     Session["fileID"] = fileId;
    }
    protected void btnDownload_Click(object sender, EventArgs e)
    {
        Stream stream = client.Download((String)Session["fileID"]);
        StreamReader reader = new StreamReader(stream);
        TextBox1.Text = reader.ReadToEnd();
    }
}

How to implement Adapter pattern in asp.net

2011-10-08T04:37:00.000-07:00

In this post,I will show you how to implement Adapter patter in asp.net.Before going to implementation details let's dive into adapter pattern definitions.

What is an Adapter Pattern?

The adapter pattern (often referred to as the wrapper pattern or simply a wrapper) is a design pattern that translates one interface for a class into a compatible interface

How’s it implemented?

1. You want to use existing class,and its interface doe not match the one you need.

2. You want to create a reusable class that cooperates with unrelated classes with incompatible interface

Problem:-

Many of us use the .net Cache class for storing objects into memory. Suppose later if we find that some other third party Cache management library that is better than existing Cache class , then the project would not change just adapter internally would call the new Cache class.

1. Here ICacheManager (Target) the interface that client wants to use

2. HttpContext (Adaptee) An implementation that needs adapting

3. CacheManager (Adapter) The class that implements the Target interface in terms of the Adaptee

Implementation

Let's start implementing the adapter patternRight click on the project and add a new class named ICacheManager and add following code inside it

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;


public interface ICacheManager
{
    void Add(string key, object data);
    void Remove(string key);
    T Get&lt;T&gt;(string key);
}


Right click on the project  and add a new class CacheManager and add following code inside it
 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
public class CacheManager : ICacheManager
{
    public void Add(string key, object data)
    {
        //Implements third party caching here
        HttpContext.Current.Cache.Add(key, data);
    }

    public void Remove(string key)
    {
        if (HttpContext.Current.Cache["key"] != null)
            HttpContext.Current.Cache.Remove(key);
    }
    public T Get&lt;T&gt;(string key)
    {
        T itemStored = (T)HttpContext.Current.Cache.Get(key);
        if (itemStored == null)
            itemStored = default(T);
        return itemStored;

    }


Add a new page and add  following code inside it


<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Adapter.aspx.cs" Inherits="Adapter" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:Button ID="btnAdd" runat="server" OnClick="btnAdd_Click" Text="Add" />
        <asp:Button ID="btnRemove" runat="server" OnClick="btnRemove_Click" Text="Remove" />
        <asp:Button ID="btnGet" runat="server" OnClick="btnGet_Click" Text="Get Value from Cache" />
    </div>
    </form>
</body>
</html>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class Adapter : System.Web.UI.Page
{
    CacheManager manager = new CacheManager();
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void btnAdd_Click(object sender, EventArgs e)
    {
        manager.Add("Key", DateTime.Now);
        
    }
    protected void btnGet_Click(object sender, EventArgs e)
    {
        Response.Write(manager.Get<DateTime>("Key").ToShortDateString());
    }
    protected void btnRemove_Click(object sender, EventArgs e)
    {
        manager.Remove("Key");
    }
}
}

How to remove duplicates elements from List using IEqualityComparer

2011-10-07T10:44:00.000-07:00

In this post,I will show you how to remove duplicate record from List using IEqualityComparer.It has two methods to support the comparison of objects for equality.

Let us suppose that you have a Employee class that has four properties EmployeeID,FirstName,LastName and Age.



public class Employee
{
    public Employee()
    {
    }
    public string EmployeeID { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public int Age { get; set; }
    public List&lt;Employee&gt; Employees
    {
        get
        {
            return new List&lt;Employee&gt;()
            {
                new Employee(){EmployeeID="E001",FirstName="F001",LastName="L001",Age=21},
                new Employee(){EmployeeID="E002",FirstName="F002",LastName="L002",Age=25},
                new Employee(){EmployeeID="E003",FirstName="F003",LastName="L003",Age=26},
                new Employee(){EmployeeID="E001",FirstName="F001",LastName="L001",Age=21},
                new Employee(){EmployeeID="E001",FirstName="F001",LastName="L001",Age=21},
            };
        }
    }
}




In the above class I have added some dummy records which have duplicates elements.Now,let's remove the duplicate elements from the above class using IEqualityComparer interface.

For this right click on the project and add a new class named EmployeeEquality and inherit this class with IEqualityComparer and implement the interface method as shown below

public class EmployeeEquality : IEqualityComparer<Employee>
{

    public bool Equals(Employee x, Employee y)
    {
        if (x.EmployeeID == y.EmployeeID && x.FirstName == y.FirstName && x.LastName == y.LastName && x.Age == y.Age)
            return true;
        return false;
    }

    public int GetHashCode(Employee obj)
    {
        //For shake of simplicity
        return obj.FirstName.GetHashCode();
    }
}

Now,let's display the record on UI
Right click on the project and add new page,and add following code inside it
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    </div>
    <asp:GridView ID="GridView1" runat="server">
    </asp:GridView>
    <asp:Button ID="btnUnSorted" runat="server" OnClick="btnUnSorted_Click" Text="Duplicates" />
    <asp:Button ID="btnWDuplicate" runat="server" OnClick="btnWDuplicate_Click" Text="Without Duplicate" />
    </form>
</body>
</html>




In the code behind add following code


using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void btnUnSorted_Click(object sender, EventArgs e)
    {
        Employee employee = new Employee();
        GridView1.DataSource = employee.Employees;
        GridView1.DataBind();
    }
    protected void btnWDuplicate_Click(object sender, EventArgs e)
    {
        Employee employee = new Employee();
        List<Employee> list = employee.Employees;
        var distinctEmployee = list.Distinct(new EmployeeEquality());
        GridView1.DataSource = distinctEmployee;
        GridView1.DataBind();
    }
}



{{Click here for live demo}}

How to sum the value of gridview column using jquery

2011-10-01T08:43:00.000-07:00

In this post I will show how to sum the value of gridview column on selection of checkbox .Let us suppose that you have a gridview which has three column named Name,Quantity and Price.Now your requirement is to sum the value of price filed on selection of checkbox.

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default2.aspx.cs" Inherits="Default2" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <script src="Scripts/jquery-1.4.1.js" type="text/javascript"></script>
    <title></title>
    <script type="text/javascript">
        $(document).ready(function () {
            var total;
            //Column index value of price field (Column index start from 1)
            var columnIndexValue = 4;
            var checked = $('input:checkbox').click(function (e) {
                var total = 0.0;
                $("tr:has(:checkbox:checked) td:nth-child(" + columnIndexValue + ")").each(function () {
                    total += parseFloat($(this).text());
                });
                $('#Sum').text("your total is:" + total.toFixed(2));
            });
        });

        
    </script>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:GridView ID="grdItems" runat="server" AutoGenerateColumns="false">
            <Columns>
                <asp:TemplateField>
                    <ItemTemplate>
                        <asp:CheckBox ID="chkItem" runat="server" />
                    </ItemTemplate>
                </asp:TemplateField>
                <asp:TemplateField HeaderText="Name">
                    <ItemTemplate>
                        <asp:Label ID="label2" Text='<%#Eval("Name") %>' runat="server" />
                    </ItemTemplate>
                </asp:TemplateField>
                <asp:TemplateField HeaderText="Quantity">
                    <ItemTemplate>
                        <asp:Label ID="Label1" Text='<%#Eval("Quantity") %>' runat="server" />
                    </ItemTemplate>
                </asp:TemplateField>
                <asp:TemplateField HeaderText="Price">
                    <ItemTemplate>
                        <asp:Label ID="Label2" Text='<%#Eval("Price") %>' runat="server" />
                    </ItemTemplate>
                </asp:TemplateField>
            </Columns>
        </asp:GridView>
    </div>
    <div id="Sum">
    </div>
    </form>
</body>
</html>


using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class Default2 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        grdItems.DataSource = new Item().Items;
        grdItems.DataBind();

    }

}
public class Item
{
    public string Name { get; set; }
    public int Quantity { get; set; }
    public decimal Price { get; set; }

    public List<Item> Items
    {
        get
        {
            return new List<Item>()
                       {
                           new Item(){Name = "Item01",Quantity = 10,Price = 180M},
                           new Item(){Name = "Item01",Quantity = 11,Price = 184M},
                           new Item(){Name = "Item01",Quantity = 12,Price = 190M},
                           new Item(){Name = "Item01",Quantity = 13,Price = 110M},
                       };
        }
    }
}


Click here for live Demo

How to compress and decompress data in c#

2011-08-17T07:38:00.000-07:00

In this post,I will show you how to compress and decompress data in  c# using GzipStream class.Below is the code for the same


using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.IO.Compression;

namespace CompressDecompress
{
    class Program
    {
        const string CompressFilePath = @"C:\temp\data.zip";
        const string Filename = @"C:\temp\data.txt";
        private const string DeCompressFilePath = @"C:\temp\data1.txt";
        static void Main(string[] args)
        {

            Compress(Filename);
            Decompress(CompressFilePath);
        }

        private static void Decompress(string compressFilePath)
        {
            using (FileStream inputStream = new FileStream(compressFilePath, FileMode.OpenOrCreate, FileAccess.ReadWrite))
            {
                using (FileStream outputStream = new FileStream(DeCompressFilePath, FileMode.Create, FileAccess.ReadWrite))
                {
                    using (GZipStream gZipStream = new GZipStream(inputStream, CompressionMode.Decompress))
                    {
                        gZipStream.CopyTo(outputStream);

                    }

                }

            }
        }

        private static void Compress(string filename)
        {
            using (FileStream inputStream = new FileStream(filename, FileMode.OpenOrCreate, FileAccess.ReadWrite))
            {
                Console.WriteLine("Size Before Compression:{0} KB", inputStream.Length / 1024);
                using (FileStream outputStream = new FileStream(CompressFilePath, FileMode.Create, FileAccess.ReadWrite))
                {
                    using (GZipStream gZipStream = new GZipStream(outputStream, CompressionMode.Compress))
                    {
                        inputStream.CopyTo(gZipStream);
                        Console.WriteLine("Size after Compression:{0} KB", outputStream.Length / 1024);
                    }

                }

            }
        }
    }
}

How to read pdf document properties in asp.net

2011-08-06T13:41:00.000-07:00

In this post, I will show you how to read the pdf document properties in asp.net.As we know that there is no- such in-built class in .net framework that read the pdf document.So,for this demo,I will used third-party library iTextSharp.

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="PdfPropertiesReader.aspx.cs"
    Inherits="PdfPropertiesReader" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <div id="pdfProperties" runat="server">
        </div>
    </div>
    <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Read Pdf Properties" />
    </form>
</body>
</html>

using System;
using System.Collections;
using System.Collections.Generic;
using iTextSharp.text;
using iTextSharp.text.pdf;
using System.Text;

public partial class PdfPropertiesReader : System.Web.UI.Page
{
    private const string FileNmae = @"C:\\temp\\asp.pdf";
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        try
        {
            StringBuilder stringBuilder = new StringBuilder();
            // create a reader (constructor overloaded for path to local file or URL)
            PdfReader reader = new PdfReader(FileNmae);
            // total number of pages
            int n = reader.NumberOfPages;
            // size of the first page
            Rectangle psize = reader.GetPageSize(1);
            float width = psize.Width;
            float height = psize.Height;
            Console.WriteLine("Size of page 1 of {0} => {1} × {2}", n, width, height);
            // file properties
            Hashtable infodict = reader.Info;
            foreach (DictionaryEntry kvp in infodict)
            {
                stringBuilder.Append(kvp.Key + "=>" + kvp.Value + "</br>");
            }

            pdfProperties.InnerHtml = stringBuilder.ToString();
        }
        catch (Exception exception)
        {

            Response.Write(exception.Message);
        }
    }
}

How to convert IEnumerable to Html table in asp.net

2011-08-06T09:32:00.000-07:00

In this post I will show how to convert IEnumerable to string (Html table).Assume you have a customer class which has three properties named FirstName,LastName and Age.Now,you want to display customer collection on UI.
For this I have created following method which retrives propertyname and value dynamically (using reflection) and return result as string
public static string ToHtmlTable(IEnumerable list, string tableSyle, string headerStyle, string rowStyle, string alternateRowStyle)

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <style type="text/css">
        .headerStyle
        {
            background-color: #abc;
        }
        .rowStyle
        {
            background-color: #def;
        }
        .alternateRowStyle
        {
            background-color: #aabbcc;
        }
    </style>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <div id="table" runat="server">
        </div>
    </div>
    </form>
</body>
</html>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        table.InnerHtml = ToHtmlTable(EmployeeDAL.Employees, "", "headerStyle", "rowStyle", "alternateRowStyle");
    }

    public static string ToHtmlTable<T>(IEnumerable<T> list, string tableSyle, string headerStyle, string rowStyle, string alternateRowStyle)
    {

        var result = new StringBuilder();
        if (String.IsNullOrEmpty(tableSyle))
        {
            result.Append("<table id=\"" + typeof(T).Name + "Table\">");
        }
        else
        {
            result.Append("<table id=\"" + typeof(T).Name + "Table\" class=\"" + tableSyle + "\">");
        }

        var propertyArray = typeof(T).GetProperties();
        foreach (var prop in propertyArray)
        {
            if (String.IsNullOrEmpty(headerStyle))
            {
                result.AppendFormat("<th>{0}</th>", prop.Name);
            }
            else
            {
                result.AppendFormat("<th class=\"{0}\">{1}</th>", headerStyle, prop.Name);
            }
        }

        for (int i = 0; i < list.Count(); i++)
        {
            if (!String.IsNullOrEmpty(rowStyle) && !String.IsNullOrEmpty(alternateRowStyle))
            {
                result.AppendFormat("<tr class=\"{0}\">", i % 2 == 0 ? rowStyle : alternateRowStyle);
            }
            else
            {
                result.AppendFormat("<tr>");
            }

            foreach (var prop in propertyArray)
            {
                object value = prop.GetValue(list.ElementAt(i), null);
                result.AppendFormat("<td>{0}</td>", value ?? String.Empty);
            }
            result.AppendLine("</tr>");
        }
        result.Append("</table>");
        return result.ToString();
    }
}

public class Employee
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public int Age { get; set; }

}
public class EmployeeDAL
{
    public static List<Employee> Employees
    {
        get
        {
            return new List<Employee>()
                       {
                           new Employee(){FirstName = "F001",LastName = "L001",Age = 31},
                           new Employee(){FirstName = "F002",LastName = "L002",Age = 32},
                           new Employee(){FirstName = "F003",LastName = "L003",Age = 33},
                           new Employee(){FirstName = "F004",LastName = "L004",Age = 34},
                       };
        }
    }
}

How to fetch header info from given url

2011-08-04T10:28:00.000-07:00

In this post I will show how to fetch header info from given url

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Text;

namespace SNIPPET_CS
{
    public class HeaderInfo
    {
        public string Key { get; set; }
        public string Value { get; set; }

        public static List<HeaderInfo> GetHttpResponseHeaders(string url)
        {
            List<HeaderInfo> headerList = new List<HeaderInfo>();
            WebRequest webRequestObject = WebRequest.Create(url);
            WebResponse responseObject = webRequestObject.GetResponse();
            if (responseObject != null)
            {
                headerList.AddRange(from string headerKey in responseObject.Headers
                                    select new HeaderInfo()
                                               {
                                                   Key = headerKey,
                                                   Value = responseObject.Headers[headerKey]
                                               });
                responseObject.Close();
            }

            return headerList;
        }

    }
    class Program
    {
        static void Main(string[] args)
        {

            // Retrieve headers:
            var headers = HeaderInfo.GetHttpResponseHeaders("http://www.google.com");

            // And output them:
            foreach (HeaderInfo headerKey in headers)
                Console.WriteLine("{0}: {1}", headerKey.Key, headerKey.Value);
        }
    }
}

How to send output of console application to file

2011-08-04T10:04:00.000-07:00

In this example,I will show how to send console output to file in c#

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;

namespace SNIPPET_CS
{
    class Program
    {
        static void Main(string[] args)
        {
            ConsoleOutput();
            Console.WriteLine("Console output saved successfully");
            Console.ReadLine();
        }
        private static void ConsoleOutput()
        {
            const string applicationPath = @"D:\Windows\System32\ipconfig.exe";
            //string ApplicationArguments = "-c -x";

            // Create a new process object
            Process processObj = new Process();

            // StartInfo contains the startup information of
            // the new process
            processObj.StartInfo.FileName = applicationPath;
            //ProcessObj.StartInfo.Arguments = ApplicationArguments;

            // These two optional flags ensure that no DOS window
            // appears
            processObj.StartInfo.UseShellExecute = false;
            processObj.StartInfo.CreateNoWindow = true;

            // If this option is set the DOS window appears again :-/
            // ProcessObj.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;

            // This ensures that you get the output from the DOS application
            processObj.StartInfo.RedirectStandardOutput = true;

            // Start the process
            processObj.Start();

            // Wait that the process exits
            processObj.WaitForExit();

            // Now read the output of the DOS application
            string result = processObj.StandardOutput.ReadToEnd();
            WriteToFile(result);
        }
        private static void WriteToFile(string result)
        {
            using (FileStream stream = new FileStream(@"C:\temp\a.txt", FileMode.OpenOrCreate, FileAccess.Write))
            {

                byte[] buffer = Encoding.Default.GetBytes(result);
                stream.Write(buffer, 0, buffer.Length);
                stream.Close();
            }
        }
    }
}

How to create an Enum value from the string

2011-07-25T10:28:00.000-07:00

This is a simple code for converting string representation to Enum

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Blog_CS
{
    public enum State { New, Ready, Stop, Reset };
    class Program
    {
        private static void Main(string[] args)
        {
            const string state = "New";
            State currentState = (State)Enum.Parse(typeof(State), state);

            if (currentState == State.New)
            {
                Console.WriteLine("Run state");

            }
        }
    }
}

How to add custom sorting for a class with IComparable interface

2011-07-24T11:23:00.000-07:00

Sometimes it necessary to sort your collection before showing it on UI.You can add custom sorting to you class just by inheriting it with IComparable interface.IComparable interface contains one single method CompareTo.

For this post I have created a class Employee which has four properties FirstName,LastName,Age and Title.This class implements IComparable interface,which means instance of the class can be compared with other instance of this class.

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;

namespace Blog_CS
{
    public class Employee : IComparable<Employee>
    {
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public int Age { get; set; }
        public string Title { get; set; }
        public static List<Employee> Employees
        {
            get
            {
                return new List<Employee>()
                           {
                               new Employee(){FirstName = "F004",LastName = "L001",Age = 21,Title = "SE"},
                               new Employee(){FirstName = "F002",LastName = "L002",Age = 41,Title = "SSE"},
                               new Employee(){FirstName = "F001",LastName = "L003",Age = 21,Title = "JE"},
                               new Employee(){FirstName = "F003",LastName = "L003",Age = 31,Title = "APM"},
                           };
            }
        }

        #region IComparable<Employee> Members
        public int CompareTo(Employee other)
        {
            return this.FirstName.CompareTo(other.FirstName);
        }
        #endregion
    }
    class Program
    {
        static void Main(string[] args)
        {
            List<Employee> employees = Employee.Employees;
            employees.Sort();
            Console.WriteLine("FirstName    LastName   Age    Title ");
            foreach (var employee in employees)
            {
                string combineddata = String.Format("{0}\t{1}\t{2}\t", employee.FirstName,
                                employee.LastName, Convert.ToInt32(employee.Age), employee.Title);
                Console.WriteLine(combineddata);
            }
        }
    }
}

How to compute hash of a file in c#

2011-07-24T05:34:00.000-07:00

This is a very simple code for calculating the hash of file in c# Namespace Required: using System.IO; using System.Security.Cryptography; Complete C# code

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Security.Cryptography;

namespace Blog_CS
{
    class Program
    {
        private const string FileName = @"D:\output.txt";
        static void Main(string[] args)
        {
            string fileHash = GetHashOfFile(FileName);
            Console.WriteLine(fileHash);
        }

        private static string GetHashOfFile(string fileName)
        {
            using (FileStream fileStream = new FileStream(fileName, FileMode.Open, FileAccess.Read))
            {
                //Create HashAlgorithm (MD5,SHA1...)
                HashAlgorithm hash = HashAlgorithm.Create("MD5");
                byte[] hashByte = hash.ComputeHash(fileStream);
                return String.Join(",", hashByte);
            }
        }
    }
}

How to convert byte array to string in c#

2011-07-24T05:09:00.000-07:00

This is a very simple code showing how to convert byte array to string in c# Note:Make sure that you have imported the namespace 'System.Text'

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Blog_CS
{
    class Program
    {
        static void Main(string[] args)
        {
            byte[] bytes = GetBytes("the quick brown fox jump over the lazy dog");
            //Convert byte array to string.
            string message = Encoding.Default.GetString(bytes);
            Console.WriteLine(message);
        }

        private static byte[] GetBytes(string message)
        {
            //Make sure that you have imported 'System.Text' namespace
            return Encoding.Default.GetBytes(message);
        }

    }
}

How to convert string to Byte array in c#

2011-07-24T05:01:00.000-07:00

This is very simple code showing how to convert string to byte array in c#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Blog_CS
{
    class Program
    {
        static void Main(string[] args)
        {
            const string message = "the quick brown fox jump over the lazy dog";
            byte[] bytes = Encoding.Default.GetBytes(message);
            Print(bytes);
        }

        private static void Print(byte[] bytes)
        {
            Console.WriteLine(String.Join(",", bytes));
        }
    }
}

How to embed exe or resource file in c# assembly

2011-07-24T03:46:00.000-07:00

Sometimes it is necessary to embed an executable (or any other file) into your application and later recreate it during runtime.In this post I will show you how to embed resource in assembly (application)

Open visual studio and create a new console application
Right click on the project and add existing file (resource)

Each individual file must be added into your solution as an “Embedded Resource”. To do this right

click in the Solution Explorer then select: Add-> Existing Item. Now locate the executable (or any other)

file of your choice and then select it. You will now see this file in the Solution Explorer. Now right

click on it and choose “Properties” Make sure "Build Action" has "Embedded Resource" selected.

C# Source Code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Reflection;
using System.IO;

namespace Embed_Resource
{
    class Program
    {
        /// <summary>
        /// This function read the name of all resouce file names from the assembly,and print those name on consolse
        /// </summary>
        private static void ReadResourceNameFromAssembly()
        {
            foreach (var resouceName in Assembly.GetExecutingAssembly().GetManifestResourceNames())
            {
                Console.WriteLine(resouceName);
            }
        }
        private static void RetriveResourceFromAssembly()
        {
            string resouceName = "Embed_Resource.data.txt";
            //Get current executing assembly
            Assembly currentAssembly = Assembly.GetExecutingAssembly();
            //Get All resources from assembly
            //Create stream for output file
            FileStream outputFileStream=new FileStream(@"D:\output.txt",FileMode.OpenOrCreate,FileAccess.ReadWrite);
            //Get stream to the resouce
            Stream resouceStream = currentAssembly.GetManifestResourceStream(resouceName);
            //copy resoucestream to outputstram
            if (resouceStream != null)
            {
                resouceStream.CopyTo(outputFileStream);
                resouceStream.Close();
            }
            outputFileStream.Close();
        }
        static void Main(string[] args)
        {
            RetriveResourceFromAssembly();
        }
    }
}

Invalid postback or callback argument. Event validation is enabled using

2011-07-15T04:16:00.000-07:00

To fix, modify the web.config file located in the /admin/ folder. Change this line:

<pages validateRequest="false" />

To:

<pages validateRequest="false" enableEventValidation="false" />

How to encrypt/decrypt data in asp.net using Symmetric algorithm

2011-07-14T03:29:00.000-07:00

In this post I am going to show you how to encrypt and decrypt data in asp.net using Symmetric algorithm.Before going to implementation details let discuss some security related terms before.
What is Hashing

Hashing is one-way algorithm, means once the data is hashed you can’t recovered it latter.

Hashing is a cryptographic function that is used to provide a secure fingerprint of data. A common usage you may have encountered is to check a file you have downloaded.

What is Encryption

If you want to secure your data, and latter you want to retrieve the original data. We used encryption because encryption is two-way processes. For encryption we requires following things

Key:Key is a piece of information that is used as an input parameter in encryption. The output of encryption is determined by the key.

Types of Encryption

There are two main types of encryption and decryption algorithms, symmetric and asymmetric.

Symmetric: In symmetric encryption we used same key for encryption and decryption( As the diagram shows the same key is used for encrypting and decrypting the message).DES, Triple DES, RC2 and AES or Rijndael are examples of symmetric algorithms

Asymmetric Encryption:

Asymmetric algorithms use a related key-pair to encrypt and decrypt data. One of the keys in the pair is typically called a public key while the other is called a private key. Data encrypted with a public key can only be decrypted with the private key, and vice-versa. PKI (public key infrastructure) is built based on asymmetric algorithm. RSA is a popular asymmetric algorithm.

What are the steps required for Encryption ?

Follow these steps to encrypt data symmetrically:

Choose an algorithm.
Create or retrieve a key.
Generate the IV.
Convert the clear text data to an array of bytes.
Encrypt the clear text byte array.
Store the encrypted data and the IV.

What are the steps required for Decryption?

Following are the steps required for decrypting the data.

Choose the same algorithm that was used to encrypt the data.
Retrieve the key that was used.
Retrieve the IV that was used.
Retrieve the encrypted data.
Decrypt the data.
Convert the decrypted data back to its original format.

Implementation

I am going to choose Triple DES algorithm for this demo.(Step#1)

Let's first generate IV (initialization vector) and Key (Step #2).For this,create a separate console application and paste following code inside Main method

static void Main(string[] args)

        {

            DESCryptoServiceProvider des = new DESCryptoServiceProvider();

            des.GenerateIV();

            des.GenerateKey();

            Console.WriteLine("Key={0}",String.Join(",",des.Key));

            Console.WriteLine("IV={0}", String.Join(",", des.IV));

            

            

        }

Run the application and note down the value of IV and Key.

Create a new class named EncryptionManager and add following code

public class EncryptionManager
{
    private byte[] Key = {89,83,45,236,140,228,180,79,209,164,231,131,28,7,110,73,140,235,118,52,225,46,202,118
    };
    private byte[] IV = { 161, 200, 187, 207, 22, 92, 119, 227 };
    public string Encrypt(string inputString)
    {
        //Step #4
        byte[] buffer = Encoding.ASCII.GetBytes(inputString);

        TripleDESCryptoServiceProvider tripleDes = new TripleDESCryptoServiceProvider()
        {
            Key = Key,
            IV = IV
        };
        //Step #4,5,6
        ICryptoTransform ITransform = tripleDes.CreateEncryptor();
        return Convert.ToBase64String(ITransform.TransformFinalBlock(buffer, 0, buffer.Length));
    }
    public string Decrypt(string inputString)
    {
        byte[] buffer = Convert.FromBase64String(inputString);
        TripleDESCryptoServiceProvider tripleDes = new TripleDESCryptoServiceProvider()
        {
            Key = Key,
            IV = IV
        };
        ICryptoTransform ITransform = tripleDes.CreateDecryptor();
        return Encoding.ASCII.GetString(ITransform.TransformFinalBlock(buffer, 0, buffer.Length));
    }
}

How to use

Create a new webpage and add following code inside it

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="EncryptDecrypt.aspx.cs" Inherits="EncryptDecrypt" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <table border="0" cellpadding="0" cellspacing="0">
        <tr>
            <td>
                <asp:TextBox ID="txtData" runat="server" TextMode="MultiLine"></asp:TextBox>
            </td>
            <td>
                <asp:TextBox runat="server" ID="txtEncrypt" TextMode="MultiLine"></asp:TextBox>
            </td>
            <td>
                <asp:TextBox runat="server" ID="txtDecrypt" TextMode="MultiLine"></asp:TextBox>
            </td>
        </tr>
        <tr>
            <td>
                <asp:Button ID="btnEncrypt" runat="server" OnClick="btnEncrypt_Click" Text="Encrypt" />
                <asp:Button ID="btnDecrypt" runat="server" Text="Decrypt" OnClick="btnDecrypt_Click" />
            </td>
        </tr>
    </table>
    </form>
</body>
</html>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Security.Cryptography;
using System.Text;
using System.IO;

public partial class EncryptDecrypt : System.Web.UI.Page
{
    EncryptionManager manager = new EncryptionManager();
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void btnEncrypt_Click(object sender, EventArgs e)
    {

        txtEncrypt.Text = manager.Encrypt(txtData.Text);
    }
    protected void btnDecrypt_Click(object sender, EventArgs e)
    {

        txtDecrypt.Text = manager.Decrypt(txtEncrypt.Text);
    }
}

How to compress response in asp.net

2011-07-13T05:08:00.000-07:00

In this post I will show you how to compress http response in asp.net for improving performance. Before going into details let's create a simple website with single page Default.aspx and add following code into it Default.aspx

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:GridView ID="grdPerson" runat="server">
        </asp:GridView>
    </div>
    </form>
</body>
</html>

Default.aspx.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            grdPerson.DataSource = Person.Persons;
            grdPerson.DataBind();
        }
    }
}


[Serializable]
public class Person
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public int Phone { get; set; }
    public string Email { get; set; }
    public static List<Person> Persons
    {
        get
        {
            return new List<Person>()
                {
                    new Person(){FirstName="Santosh",LastName="Singh",Phone=1213123,Email="santosh@gmail.com"},
                    new Person(){FirstName="Ashok",LastName="Singh",Phone=1213123,Email="ashok@gmail.com"},
                    new Person(){FirstName="Bill",LastName="Gates",Phone=1213123,Email="bill@gmail.com"},
                };
        }

    }
    public override string ToString()
    {
        return string.Format(@"FirstName {0} & LastName {1} Phone {2} Email {3}", this.FirstName, this.LastName, this.Phone, this.Email);
    }
}

Now,press F5 and see the response result in FireBug.You will see the response result something like below

Note down the Content-Length size(in my case is 1720) Let's compress the response.For this right click on website ,and add Global.asax file.Inside this file add a method named

void Application_BeginRequest(object sender, EventArgs e)
{

}

Inside it paste the following code and see the result in FireBug

 void Application_BeginRequest(object sender, EventArgs e)
    {
        HttpContext incoming = HttpContext.Current;
        string oldpath = incoming.Request.Path.ToLower();
        incoming.Response.Filter = new System.IO.Compression.GZipStream(incoming.Response.Filter, System.IO.Compression.CompressionMode.Compress);
        HttpContext.Current.Response.AppendHeader("Content-encoding", "gzip");
        HttpContext.Current.Response.Cache.VaryByHeaders["Accept-encoding"] = true;

    }

Check the Content-Length property after compression. Note:For compress/decompression I am using .net framework class GZipStream

How to Hash User Passwords in asp.net

2011-07-11T05:25:00.000-07:00

In this post I will show you how to hash user password in asp.net Before going into implementation details,let first design the table structure.For the shake of simplicity I have taken only some fields.

Right click on the website,add asp.net special folder App_Code. Right click on App_Code folder and add new item Linq to Sql classes and drag the table from Server Explorer to Linq to sql classes surface.

Again right click App_Code and add new class named UserManager.cs inside App_Code folder.Now paste the following code in it

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Security.Cryptography;
using System.Web.Security;
public class UserManager
{
   
    private static string CreateSalt(int size)
    {
        //Generate a cryptographic random number.
        RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider();
        byte[] buff = new byte[size];
        rng.GetBytes(buff);
        // Return a Base64 string representation of the random number.
        return Convert.ToBase64String(buff);
    }
    public static string CreatePasswordHash(string pwd, string salt)
    {
        string saltAndPwd = String.Concat(pwd, salt);
        string hashedPwd =FormsAuthentication.HashPasswordForStoringInConfigFile(saltAndPwd, "sha1");
        return hashedPwd;
    }
    public void CreaetUser(string userName, string password, string email)
    {
        SecureLoginDataContext dc = new SecureLoginDataContext();
        string salt = CreateSalt(8);
        User user = new User();
        user.Email = email;
        user.Salt = salt;
        user.Password = CreatePasswordHash(password, salt);
        user.UserName = userName;
        dc.Users.InsertOnSubmit(user);
        dc.SubmitChanges();
    }

    public static User GetUserDetails(string username)
    {
        SecureLoginDataContext dc = new SecureLoginDataContext();
        User result = (from c in dc.Users
                         where c.UserName.Equals(username)
                         select c).FirstOrDefault();

        return result;
    }
   
}

Add three new pages to your website named Login.aspx,Welcome.aspx and Registration.aspx Open Login.aspx and add following code in it Login.aspx

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Login.aspx.cs" Inherits="Login" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <style type="text/css">
        .style1
        {
            width: 100%;
        }
    </style>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    
        <table class="style1">
            <tr>
                <td>
                    UserName</td>
                <td>
                    <asp:TextBox ID="txtUserName" runat="server"></asp:TextBox>
                </td>
            </tr>
            <tr>
                <td>
                    Password</td>
                <td>
                    <asp:TextBox ID="txtPassword" runat="server" TextMode="Password" Width="128px"></asp:TextBox>
                </td>
            </tr>
            <tr>
                <td>
                    &nbsp;</td>
                <td>
                    <asp:Button ID="btnLogin" runat="server" Text="Login" 
                        onclick="btnLogin_Click" />
                </td>
            </tr>
        </table>
    
    </div>
    </form>
    <p>
        <a href="Registration.aspx">Not a registred member</a></p>
</body>
</html>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class Login : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void btnLogin_Click(object sender, EventArgs e)
    {
        User user = UserManager.GetUserDetails(txtUserName.Text);
        string tempHashPassword = UserManager.CreatePasswordHash(txtPassword.Text, user.Salt);
        //Compare tempHashPassword with haspassword stored in database.
        if (tempHashPassword == user.Password)
        {
            Response.Redirect("Welcome.aspx");
        }
        else
        {
            Response.Write("Invalid username/password");
        }
    }
}

open Registration.aspx and add following code in it

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Registration.aspx.cs" Inherits="Registration" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
 
    <style type="text/css">
        .style1
        {
            width: 100%;
        }
    </style>
 
</head>
<body>
    <form id="form1" runat="server">

    <table class="style1">
        <tr>
            <td>
                UserName</td>
            <td>
                <asp:TextBox ID="txtUserName" runat="server"></asp:TextBox>
            </td>
        </tr>
        <tr>
            <td>
                Password</td>
            <td>
                <asp:TextBox ID="txtPassword" runat="server" TextMode="Password"></asp:TextBox>
            </td>
        </tr>
        <tr>
            <td>
                Email</td>
            <td>
                <asp:TextBox ID="txtEmail" runat="server"></asp:TextBox>
            </td>
        </tr>
        <tr>
            <td>
                &nbsp;</td>
            <td>
                <asp:Button ID="btnCreate" runat="server" onclick="btnCreate_Click" 
                    Text="Create" />
            </td>
        </tr>
    </table>

    </form>
  
</body>
</html>

Registration.aspx.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class Registration : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void btnCreate_Click(object sender, EventArgs e)
    {
        UserManager user = new UserManager();
        user.CreaetUser(txtUserName.Text, txtPassword.Text, txtEmail.Text);
        Response.Redirect("Login.aspx");
    }
}

How to display progress indicator during ajax call in asp.net[Jquery]

2011-06-27T11:59:00.000-07:00

In this post I will show you how to display progress indicator during ajax call.

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Jquery_Progress.aspx.cs"
    Inherits="Jquery_Progress" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <script src="Scripts/jquery-1.4.1.js" type="text/javascript"></script>
    <style type="text/css">
        .loader
        {
            display: none;
            background-color: Red;
            width: 100px;
        }
    </style>
    <script language="javascript" type="text/javascript">
        $(document).ready(function () {
            $("#btnLoad").click(function (e) {
                e.preventDefault();
                $("#gvData").html("");
                $("#loader").show();
                sendData();
            });
        });
        function sendData() {
            var loc = window.location.href;
            loc = (loc.substr(loc.length - 1, 1) == "/") ? loc + "Jquery_Progress.aspx" : loc;
            $.ajax({
                type: "POST",
                url: loc + "/GetAllProducts",
                contentType: "application/json;charset=utf-8",
                dataType: "json",
                success: function (msg) {
                    $("#loader").hide();
                    $("#gvData").html(msg.d);
                },
                error: function () {
                    alert("An unexpected error has occurred during processing.");
                }
            });
        }
    </script>
</head>
<body>
    <form id="form1" runat="server">
    <asp:Button ID="btnLoad" runat="server" Text="LoadProduct" /><br />
    <div id="gvData">
    </div>
    <div id="loader" class="loader">
        Loading....</div>
    </form>
</body>
</html>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.Services;
using System.Web.Script.Services;
using System.Web.Script.Serialization;
using System.Text;

public partial class Jquery_Progress : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    [WebMethod]
    [ScriptMethod]
    public static string GetAllProducts()
    {
        //Comment below line for production server
        System.Threading.Thread.Sleep(3000);
        StringBuilder sb=new StringBuilder();
        JavaScriptSerializer json=new JavaScriptSerializer();
        List<Product> products = ProductDAL.GetProducts();
        json.Serialize(products, sb);
       return sb.ToString();
    }
}
public class Product
{
    public int ProductID { get; set; }
    public string ProductName { get; set; }
    public string Description { get; set; }
}
public class ProductDAL
{
    public static List<Product> GetProducts()
    {
        return new List<Product>()
                   {
                       new Product() {ProductID = 1, ProductName = "P001", Description = "Desc01"},
                       new Product() {ProductID = 2, ProductName = "P002", Description = "Desc02"},
                       new Product() {ProductID = 3, ProductName = "P003", Description = "Desc03"},
                       new Product() {ProductID = 4, ProductName = "P004", Description = "Desc04"},
                       new Product() {ProductID = 5, ProductName = "P005", Description = "Desc05"},
                   };
    }
}

Highlighting rows/cells of a GridView on hover

2011-06-27T10:38:00.000-07:00

In this post I will show you how to highlight grid view row on mouseover using jquery.

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="GridviewRowColorChange.aspx.cs"
    Inherits="GridviewRowColorChange" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <script src="Scripts/jquery-1.4.1.js" type="text/javascript"></script>
    <style type="text/css">
        .highlight
        {
            background-color:#9999FF;
        }  
        td
        {
            cursor: pointer;
        }
    </style>
    <script type="text/javascript">
        $(document).ready(function () {
            $("#<%=gvProducts.ClientID %> tr").mouseover(function () {
                $(this).addClass("highlight");
            });
            $("#<%=gvProducts.ClientID %> tr").mouseout(function () {
                $(this).removeClass("highlight");
            });
        });
    </script>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:GridView ID="gvProducts" runat="server">
        </asp:GridView>
    </div>
    </form>
</body>
</html>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class GridviewRowColorChange : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if(!IsPostBack)
        {
            gvProducts.DataSource = ProductDAL.GetProducts();
            gvProducts.DataBind();
        }
    }
}
public class Product
{
    public int ProductID { get; set; }
    public string ProductName { get; set; }
    public string Description { get; set; }
}
public class ProductDAL
{
    public static List<Product> GetProducts()
    {
        return new List<Product>()
                   {
                       new Product() {ProductID = 1, ProductName = "P001", Description = "Desc01"},
                       new Product() {ProductID = 2, ProductName = "P002", Description = "Desc02"},
                       new Product() {ProductID = 3, ProductName = "P003", Description = "Desc03"},
                       new Product() {ProductID = 4, ProductName = "P004", Description = "Desc04"},
                       new Product() {ProductID = 5, ProductName = "P005", Description = "Desc05"},
                   };
    }

}

How to select/deselect all checkbox in gridview using jquery

2011-06-27T10:03:00.000-07:00

In this post I will show how to select/deselect checkbox present inside gridview using jquery.

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="GridViewSelectAll.aspx.cs"
    Inherits="GridViewSelectAll" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <script src="Scripts/jquery-1.4.1.js" type="text/javascript"></script>
    <script type="text/javascript">
        $(document).ready(function () {
            $("#<%=gvProducts.ClientID%> input[id$='chkAll']:checkbox").click(function () {
                $("#<%=gvProducts.ClientID%> input[id*='chkSelected']:checkbox").attr('checked', $(this).is(':checked'));
            });
        });
    </script>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:GridView runat="server" ID="gvProducts" AutoGenerateColumns="false">
            <Columns>
                <asp:TemplateField>
                    <HeaderTemplate>
                        <input type="checkbox" id="chkAll" runat="server" value='<%#Eval("ProductID") %>' />
                    </HeaderTemplate>
                    <ItemTemplate>
                        <input type="checkbox" id="chkSelected" runat="server" />
                    </ItemTemplate>
                </asp:TemplateField>
                <asp:BoundField DataField="ProductName" HeaderText="ProductName" />
                <asp:BoundField DataField="Description" HeaderText="Description" />
            </Columns>
        </asp:GridView>
    </div>
    </form>
</body>
</html>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class GridViewSelectAll : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        gvProducts.DataSource = ProductDAL.GetProducts();
        gvProducts.DataBind();
    }
}
public class Product
{
    public int ProductID { get; set; }
    public string ProductName { get; set; }
    public string Description { get; set; }
}
public class ProductDAL
{
    public static List<Product> GetProducts()
    {
        return new List<Product>()
                   {
                       new Product() {ProductID = 1, ProductName = "P001", Description = "Desc01"},
                       new Product() {ProductID = 2, ProductName = "P002", Description = "Desc02"},
                       new Product() {ProductID = 3, ProductName = "P003", Description = "Desc03"},
                       new Product() {ProductID = 4, ProductName = "P004", Description = "Desc04"},
                       new Product() {ProductID = 5, ProductName = "P005", Description = "Desc05"},
                   };
    }

}

How to enlarge image on mouseover in asp.net using jquery

2011-06-26T07:04:00.000-07:00

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Img_Enlarge.aspx.cs" Inherits="Img_Enlarge" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <script type="text/javascript" src="Scripts/jquery-1.4.1.js"></script>
    <style type="text/css">
        .thumbnail
        {
            height: 100px;
            width: 100px;
            position: relative;
        }
        .image
        {
            position: relative;
            width: 400px;
            height: 250px;
        }
    </style>
    <script language="javascript" type="text/javascript">
        $(document).ready(function () {
            $(".thumbnail").mouseover(function () {
                $(".thumbnail").css("opacity", ".5");
                $(this).animate({ opacity: 1.0 });
                $("#imgContainer").append("<img class='image' src='" + $(this).attr("src") + "' />");

            });
            $(".thumbnail").mouseout(function () {
                $(".thumbnail").css("opacity", "1.0");
                $(".image").remove();
            });
        });
       
    </script>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    </div>
    </form>
    <div align="center">
        <img alt="" class="thumbnail" src="Images/Tree.jpg" />
        <img class="thumbnail" src="Images/dock.jpg" alt="" />
        <img class="thumbnail" src="Images/forest.jpg" alt="" />
        <img class="thumbnail" src="Images/garden.jpg" alt="" />
        <div id="imgContainer">
        </div>
    </div>
</body>
</html>

How to Implement jQuery UI slider with ASP.NET

2011-06-22T03:23:00.000-07:00

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Slider_Demo.aspx.cs" Inherits="Slider_Demo" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <link type="text/css" rel="Stylesheet" href="http://ajax.microsoft.com/ajax/jquery.ui/1.8.5/themes/start/jquery-ui.css" />
    <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js">
    </script>
    <script type="text/javascript" src="http://ajax.microsoft.com/ajax/jquery.ui/1.8.5/jquery-ui.min.js">
    </script>
    <title></title>
    <script type="text/javascript">
        $(document).ready(function () {
            $("#slider").slider(
            {
                min: <%=MinValue%>,
                max: <%=MaxValue%>,
                step: <%=Step %>,
                slide: function (event, ui) {
                    $("#txtValue").val(ui.value);
                }
            });
        });
    
    </script>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <div id="slider" style="width: 200px;">
        </div>
        <br />
        <asp:TextBox ID="txtValue" runat="server"></asp:TextBox>
    </div>
    </form>
</body>
</html>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class Slider_Demo : System.Web.UI.Page
{
    public const int MinValue = 0;
    public const int MaxValue = 100;
    public const int Step = 5;
    protected void Page_Load(object sender, EventArgs e)
    {

    }
}

How to Invoke required field validator through javascript in asp.net

2011-06-21T04:25:00.000-07:00

In this post I will show you how to invoke required field validator through java script in asp.net.

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="ReqJs.aspx.cs" Inherits="ReqJs" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <script type="text/javascript">
        function PerformCheck() {
            if (Page_ClientValidate()) {
                //Do some more stuff here
                alert("Page Is Valid");
            }

        }
    
    </script>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        FirstName:
        <asp:TextBox runat="server" ID="txtFirstName"></asp:TextBox>
        <asp:RequiredFieldValidator ErrorMessage="*" Text="Please Enter first name" ControlToValidate="txtFirstName"
            runat="server" /><br />
        LastName:
        <asp:TextBox runat="server" ID="txtLastName"></asp:TextBox>
        <asp:RequiredFieldValidator ErrorMessage="*" Text="Please enter last name" ControlToValidate="txtLastName"
            runat="server" /><br />
        <input type="submit" id="btnSubmit" onclick="PerformCheck();" value="Validate" />
    </div>
    </form>
</body>
</html>

How to display rss feed in asp.net

2011-06-18T10:12:00.000-07:00

In this post I will show you how to display rss feed in asp.net using XmlDataSource and DataList control. Rss_cs.aspx

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="RSS_CS.aspx.cs" Inherits="RSS_CS" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:TextBox ID="txtUrl" runat="server" Width="349px"></asp:TextBox>
        <asp:Button ID="btnLoad" runat="server" Text="Load" OnClick="btnLoad_Click" />
        <br />
        <asp:DataList ID="dlRss" runat="server">
            <ItemTemplate>
                <%#XPath("title") %><br />
                <i>
                    <%#XPath("description") %></i> <i>
                        <br />
                        <%#XPath("pubdate") %></i> <b><a href='<%#XPath("link") %>'>
                            <%#XPath("link") %></a></b><br />
            </ItemTemplate>
        </asp:DataList>
        <asp:XmlDataSource ID="xml" runat="server" XPath="rss/channel/item"></asp:XmlDataSource>
    </div>
    </form>
</body>
</html>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class RSS_CS : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        
        
    }
    protected void btnLoad_Click(object sender, EventArgs e)
    {
        
        if (txtUrl.Text != "")
        {
            xml.DataFile = txtUrl.Text;
            dlRss.DataSourceID = xml.ClientID;
        }
    }
}

Best Practices for Speeding Up Your Web Site

2011-05-08T10:18:00.000-07:00

Today I found a greate article for best practices for making web pages fast.The list includes 34 best practices divided into 7 categories.

1) Content

    * Minimize HTTP Requests
    * Reduce DNS Lookups
    * Avoid Redirects
    * Make Ajax Cacheable
    * Post-load Components
    * Preload Components
    * Reduce the Number of DOM Elements
    * Split Components Across Domains
    * Minimize the Number of iframes

2) Server

    * Use a Content Delivery Network
    * Add an Expires or a Cache-Control Header
    * Gzip Components
    * Configure ETags
    * Flush the Buffer Early
    * Use GET for AJAX Requests

3) CSS

    * Put Stylesheets at the Top
    * Avoid CSS Expressions
    * Choose over @import
    * Avoid Filters

4) Javascript

    * Put Scripts at the Bottom
    * Make JavaScript and CSS External
    * Minify JavaScript and CSS
    * Remove Duplicate Scripts
    * Minimize DOM Access
    * Develop Smart Event Handlers

5) Cookie

    * Reduce Cookie Size
    * Use Cookie-free Domains for Components

6) Images

    * Optimize Images
    * Optimize CSS Sprites
    * Don’t Scale Images in HTML
    * Make favicon.ico Small and Cacheable

7) Mobile

    * Keep Components under 25K
    * Pack Components into a Multipart Document

For details check out this

How to Programmatically add JavaScript File to Asp.Net page?

2011-05-02T01:52:00.000-07:00

In this post I will show you how to add JavaScript files programmatically to your asp.net page.

Just add this code to the Page_Init event handler on your page:

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Blog_Tips.aspx.cs" Inherits="Blog_Tips" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    
        How to Programmatically add JavaScript File to Asp.Net page?
    
    </div>
    </form>
</body>
</html>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;

public partial class Blog_Tips : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }

    protected void Page_Init(object sender, EventArgs e)
    {
        HtmlGenericControl javascript = new HtmlGenericControl("script");
        javascript.Attributes["type"] = "text/javascript";
        javascript.Attributes["src"] = "Scripts/jquery-1.3.2.min.js";
        Page.Header.Controls.Add(javascript);
    }
}

Display parent child data in GridView using usercontrol

2011-04-28T03:17:00.000-07:00

In this post I am going to show how to display parent child data in gridview using usercontrol.

Open Visual studio and create a new website
Right click on App_Code folder ,and add new class named Customer and add following code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;


public class Customer
{
    public Customer()
    {
        
    }
    public Customer(int id, string name)
    {
        this.CustomerID = id;
        this.CustomerName = name;
        PhoneList = new List<PhoneNumber>();
    }

    public int CustomerID { get; set; }
    public string CustomerName { get; set; }
    public List<PhoneNumber> PhoneList { get; set; }
}

Right click on App_Code folder and add a new class PhoneNumber and add following code into it

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

public class PhoneNumber
{
    public int ID { get; set; }
    public string Number { get; set; }
    public PhoneNumber()
    {
    }
    public PhoneNumber(int id, string number)
    {
        this.ID = id;
        this.Number = number;

    }
}

Right click on the website,and add an usercontrol named PhoneNumbers.ascx and add following code into it

<%@ Control Language="C#" AutoEventWireup="true" CodeFile="PhoneNumbers.ascx.cs" Inherits="PhoneNumbers" %>
<asp:GridView ShowHeader="False" ID="GridView1" runat="server" GridLines="None"
    AutoGenerateColumns="False">
    <Columns>
        <asp:BoundField DataField="Number" HeaderText="Number" />
    </Columns>
</asp:GridView>

Open the code behind and add following code into it

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Collections;
using System.ComponentModel;

public partial class PhoneNumbers : System.Web.UI.UserControl
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    private IEnumerable _data;
    [EditorBrowsable()]
    public IEnumerable DataSource
    {
        get { return _data; }
        set
        {
            _data = value;
            DataChange(value);
        }
    }
    private void DataChange(IEnumerable value)
    {
        GridView1.DataSource = value;
        GridView1.DataBind();
    }
}

Open Default.aspx page and add GridView control as below

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

<%@ Register Src="PhoneNumbers.ascx" TagName="PhoneNumbers" TagPrefix="uc1" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    </div>
    <asp:GridView AutoGenerateColumns="False" ID="GridView1" runat="server" CellPadding="4"
        ForeColor="#333333" GridLines="None">
        <AlternatingRowStyle BackColor="White" ForeColor="#284775" />
        <Columns>
            <asp:BoundField DataField="CustomerID" HeaderText="ID" />
            <asp:BoundField DataField="CustomerName" HeaderText="Customer Name" />
            <asp:TemplateField HeaderText="Phone Numbers">
                <ItemTemplate>
                    <uc1:PhoneNumbers ID="PhoneNumbers2" runat="server" DataSource='<%#Eval("PhoneList")%>' />
                </ItemTemplate>
            </asp:TemplateField>
        </Columns>
        <EditRowStyle BackColor="#999999" />
        <FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
        <HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
        <PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" />
        <RowStyle BackColor="#F7F6F3" ForeColor="#333333" />
        <SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" />
        <SortedAscendingCellStyle BackColor="#E9E7E2" />
        <SortedAscendingHeaderStyle BackColor="#506C8C" />
        <SortedDescendingCellStyle BackColor="#FFFDF8" />
        <SortedDescendingHeaderStyle BackColor="#6F8DAE" />
    </asp:GridView>
    </form>
</body>
</html>

Open Default.aspx.cs page and add following code on Page_Load event

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if(!IsPostBack)
        {
            List<Customer> list = new List<Customer>();
            list.Add(new Customer(1, "John"));
            list.Add(new Customer(2, "Joe"));
            list.Add(new Customer(3, "Don"));
            list[0].PhoneList.Add(new PhoneNumber(1, "555 - 555 - 555"));
            list[0].PhoneList.Add(new PhoneNumber(1, "666 - 555 - 555"));
            list[0].PhoneList.Add(new PhoneNumber(1, "111 - 555 - 555"));
            list[1].PhoneList.Add(new PhoneNumber(2, "222 - 555 - 555"));
            list[1].PhoneList.Add(new PhoneNumber(2, "333 - 555 - 555"));
            list[2].PhoneList.Add(new PhoneNumber(3, "444 - 555 - 555"));
            GridView1.DataSource = list;
            GridView1.DataBind(); 
        }
    }
}

How to download file asynchronously from webserver in asp.net

2011-04-20T01:40:00.000-07:00

In this post I am going to show how to download file asynchronously from server using asp.net.

Open Visual Studio and create a new WebApplication or WebSite

Open Default.aspx page and paste following code

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default"
    Async="true" %>

<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <title></title>
    <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.4/jquery.min.js"></script>
</head>
<body>
    <script type="text/javascript">
        function WaitProgress() {
            $("#Indicator").text("please wait...");
        }
        function FinishProgress(contentState) {
            $("#Indicator").text(contentState);
        }
    </script>
    <form id="form1" runat="server">
    <asp:Button ID="btnDownload" runat="server" Text="DownLoadData" OnClientClick="WaitProgress();"
        OnClick="btnDownload_Click" />
    <p id="Indicator">
    </p>
    </form>
</body>
</html>

Open Default.aspx.cs file and pate following code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Threading;
using System.Net;

public partial class _Default : System.Web.UI.Page
{
    private const string FILE_PATH = @"C:\Temp\test.pdf";
    protected void btnDownload_Click(object sender, EventArgs e)
    {
        DownLoadFile();
    }
    private void DownLoadFile()
    {
        //define the url
        string url = "http://www.daikodo.com/genki-back/back-img/10genki-2.jpg";
        //define the local path
        string filepath = FILE_PATH;
        Uri uri = new Uri(url);
        WebClient client = new WebClient();
        client.DownloadFileCompleted += new System.ComponentModel.AsyncCompletedEventHandler(client_DownloadFileCompleted);
        client.Credentials = new NetworkCredential();
        client.DownloadFileAsync(uri, filepath);
    }

    void client_DownloadFileCompleted(object sender, System.ComponentModel.AsyncCompletedEventArgs e)
    {
        string contentState = "File Downloaded Successfully!!!";
        if (e.Error != null)
        {
            contentState = e.Error.Message;
        }
        else
        {
            object userstate = e.UserState;
            this.ClientScript.RegisterStartupScript(this.GetType(), "finishDownload", "FinishProgress('" + contentState + "');", true);
        }
    }



}

How to use jquery dialog in asp.net

2011-01-29T02:09:00.000-08:00

In this post I am going to show you how to use jquery model dialog in asp.net.

Note:Please make sure that you have downloaded the jquery and jqueyui library.

Start visual studio

Select File/New Project

Choose a Web Site Template -for this example I used Empty Web Site

Right click on empty web site and add new class named Person.cs and paste following code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

public class Person
{
    public string Name { get; set; }
    public string Email { get; set; }

    public static List<Person> GetAll()
    {
        List<Person> list = new List<Person>()
            {
                new Person{Name="John",Email="john@doe.com"},
                new Person{Name="Admin",Email="admin@doe.com"},
            };
        HttpContext.Current.Session["Add"] = list; 
        return list;
    }
}

Right click on empty website and add new item (Ajax Enabled WCF Service) and modified the code of Service.cs as below

Service.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.ServiceModel.Activation;
using System.ServiceModel.Web;
using System.Text;
using System.Web;

[ServiceContract(Namespace = "")]
[AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
public class Service
{
    [WebGet(UriTemplate = "Insert/?name={name}&email={email}", ResponseFormat = WebMessageFormat.Json, BodyStyle = WebMessageBodyStyle.Bare)]
    [OperationContract]
    public string InsertPerson(string name, string email)
    {
        string data = string.Empty;
        List<Person> list = null;
        if (HttpContext.Current.Session["Add"] == null)
        {
            list = Person.GetAll();

        }
        else
        {
            list = (List<Person>)HttpContext.Current.Session["Add"];
            if (!string.IsNullOrEmpty(name) || !string.IsNullOrEmpty(email))
            {
                list.Add(new Person { Name = name, Email = email });
                HttpContext.Current.Session["Add"] = list;
                data = "<tr><td>" + name + "</td> <td>" + email + "</td></tr>";

            }
            else
            {
                data = "Failure";
            }
         
        }

        return data;
    }
}

Right click on Website and add new item named Default.aspx and add following code

<%@ Page Language="C#" AutoEventWireup="true" EnableEventValidation="false" CodeFile="Default.aspx.cs"
    Inherits="_Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <style>
        body
        {
            font-size: 80%;
        }
        label, input
        {
            display: block;
        }
        input.text
        {
            margin-bottom: 12px;
            width: 95%;
            padding: .4em;
        }
        fieldset
        {
            padding: 0;
            border: 0;
            margin-top: 25px;
        }
        h1
        {
            font-size: 1.2em;
            margin: .6em 0;
        }
        div#users-contain
        {
            width: 350px;
            margin: 20px 0;
        }
        div#users-contain table
        {
            margin: 1em 0;
            border-collapse: collapse;
            width: 100%;
        }
        div#users-contain table td, div#users-contain table th
        {
            border: 1px solid #eee;
            padding: .6em 10px;
            text-align: left;
        }
        .ui-dialog .ui-state-error
        {
            padding: .3em;
        }
        .validateTips
        {
            border: 1px solid transparent;
            padding: 0.3em;
        }
    </style>
    <link href="Style/jquery-ui-1.8.7.custom.css" rel="stylesheet" type="text/css" />
    <script src="Scripts/jquery-1.4.1.js" type="text/javascript"></script>
    <script src="Scripts/jquery-ui-1.8.7.custom.min.js" type="text/javascript"></script>
    <script type="text/javascript">
      
    </script>
    <script type="text/javascript">
        $(document).ready(function () {
            $('#editPerson').dialog({
                autoOpen: false,
                model: true,
                draggable: true, title: "Add Person",
                buttons: {
                    "Create an account": function () {
                        var name = $("#name").val();
                        var email = $("#email").val();
                        $.getJSON("Service.svc/Insert", { name: name, email: email }, function (data) {
                            $('#grdPerson tbody tr:last').after(data);
                            $("#editPerson").dialog("close");
                        });
                    },
                    Cancel: function () {
                        $(this).dialog("close");
                    }
                },
                open: function (type, data) {
                    $(this).parent().appendTo("form");
                }
            });
        });
        //Show Dialog function
        function showDialog(id) {
            $('#' + id).dialog("open");
        } 
    </script>
</head>
<body>
    <form id="form1" runat="server">
    <div style="text-align: center">
        <asp:GridView ID="grdPerson" runat="server" AutoGenerateColumns="false" Width="400">
            <Columns>
                <asp:BoundField DataField="Name" HeaderText="Name" />
                <asp:BoundField DataField="Email" HeaderText="Email" />
            </Columns>
        </asp:GridView>
        <div id="editPerson" title="Create new user">
            <fieldset>
                <label for="name">
                    Name</label>
                <input type="text" name="name" id="name" class="text ui-widget-content ui-corner-all" />
                <label for="email">
                    Email</label>
                <input type="text" name="email" id="email" value="" class="text ui-widget-content ui-corner-all" />
            </fieldset>
        </div>
        <input type="button" id="btnAdd" runat="server" value="Add New Person" onclick="showDialog('editPerson');" />
    </div>
    </form>
</body>
</html>

How to: Return multiple response from wcf

2011-01-08T02:59:00.000-08:00

Imagine you have a wcf application that return xml response but after some time your requirements changed that we want to return multiple response (XML /Json) from the same service.How do you achieved this? Earlier it was nightmare for developer to return multiple response from .net. Now you have a good news that you can return multiple response from wcf 4.0 with a very minimal changes.

So In this post I am going to show you how to return multiple response from wcf in .net framework 4.0

Open visual studio and create an empty website.

Right click on the website project and add a new wcf service.It will create three files named Service.svc,IService and Service.cs.

Open IService.cs file and paste the following code

Open Service.cs file and add following code

Right click on App_Code folder and add new class named Person and add following code(This class contains dummy data for demo purpose only )

Till now whaterver I have created so for is normal process for creating wcf service application in .net.Now open web.config and go to endpointBehaviours section and set automaticFormatSelectionEnabled equal to true .

<?xml version="1.0"?>
<!--
  For more information on how to configure your ASP.NET application, please visit
  http://go.microsoft.com/fwlink/?LinkId=169433
  -->
<configuration>
    <system.serviceModel>
        <services>
            <service name="Service" behaviorConfiguration="ServiceBehavior">
                <endpoint address="" binding="webHttpBinding" behaviorConfiguration="JsonBehavior" bindingConfiguration="" contract="IService"/>
            </service>
        </services>
        <behaviors>
            <endpointBehaviors>
                <behavior name="JsonBehavior">
                    <webHttp automaticFormatSelectionEnabled="true"/>
                </behavior>
            </endpointBehaviors>
            <serviceBehaviors>
                <behavior name="ServiceBehavior">
                    <!-- To avoid disclosing metadata information, set the value below to false and remove the metadata endpoint above before deployment -->
                    <serviceMetadata httpGetEnabled="true"/>
                    <!-- To receive exception details in faults for debugging purposes, set the value below to true.  Set to false before deployment to avoid disclosing exception information -->
                    <serviceDebug includeExceptionDetailInFaults="true"/>
                </behavior>
            </serviceBehaviors>
        </behaviors>
    </system.serviceModel>
    <system.web>
        <compilation debug="true" targetFramework="4.0">
        </compilation>
        <pages controlRenderingCompatibilityVersion="3.5" clientIDMode="AutoID"/></system.web>
</configuration>

What does automaticFormatSelectionEnabled do? It is a new property introduced in wcf 4.0 that do following task.

When enabled, automatic formatting chooses the best format in which to return the response. It determines the best format by checking the following, in order:

The media types in the request message’s Accept header.
The content-type of the request message.
The default format setting in the operation.
The default format setting in the WebHttpBehavior.

Now our wcf service application is complete and ready to use.Let's consume this service using Jquery.Open Default.aspx page (in my case ) and paste following code.

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <script src="Scripts/jquery-1.3.2.js" type="text/javascript"></script>
    <script type="text/javascript">
        $(document).ready(function () {
            $("#btnJson").click(function () {
                JsonCall();
            });
            $("#btnXml").click(function () {
                XmlCall();
            });
        });
        function XmlCall() {
            $.ajax(
            {
                type: "POST",
                url: "Service.svc/GetAll",
                dataType: "xml",
                contentType: "application/xml",
                data: "",
                success: function (ret) {
                    alert(ret);
                }
            });
        }
        function JsonCall() {
            $.ajax(
            {
                type: "POST",
                url: "Service.svc/GetAll",
                dataType: "json",
                contentType: "application/json",
                data: "{}",
                success: function (ret) {
                    alert(ret);
                }
            });
        }
    </script>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <input type="button" id="btnJson" value="Get JSON" />
        <input type="button" id="btnXml" value="Get XML" />
    </div>
    </form>
</body>
</html>

In the above page I have added two functions XmlCall and JsonCall function and I am calling these two functions on button click.Run and test the application you will see that same service is returning multiple respnse.

I have attached the full source code

How to:Create wcf application without using config file

2010-12-18T11:32:00.000-08:00

In this post i am going to show you how to create wcf application without using config file. Let's start the tutorial.

Open visual studio and create a new console application
Right click on the project and add reference to following assembly

using System.ServiceModel;

Open Program.cs file and paste following code

[ServiceContract]
    interface IService
    {
        [OperationContract]
        string HelloWorld(string strMessage);
    }
    public class ServiceImp : IService
    {
        [OperationBehavior]
        public string HelloWorld(string strMessage)
        {
            return ("Hello " + strMessage + "!");
        }
    }

Now Add following code inside main method

static void Main(string[] args)
        {
            //Create a URI to serve as the base address
            Uri httpUrl = new Uri("http://localhost:8090/MyService");
            //Create ServiceHost
            ServiceHost host = new ServiceHost(typeof(ServiceImp), httpUrl);
            //Add a service endpoint
            host.AddServiceEndpoint(typeof(IService), new WSHttpBinding(), "");
            //Enable metadata exchange
            ServiceMetadataBehavior smb = new ServiceMetadataBehavior();
            smb.HttpGetEnabled = true;
            host.Description.Behaviors.Add(smb);
            Binding mexBinding = MetadataExchangeBindings.CreateMexHttpBinding();
            //Adding metadata exchange endpoint
            host.AddServiceEndpoint(typeof(IMetadataExchange), mexBinding, "mex");
            //Start the Service
            host.Open();
            Console.WriteLine("Host is running... Press  key to stop");
            Console.ReadLine();

        }

Now press F5 and see the message.If everything is fine then you will see a message "Host is running ...Press key to stop"

Now it's time to create Client application

Right click on solution and create a new console application named WcfClient
Open the Program.cs file and paste the following code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ServiceModel;

namespace WCFClient
{
    [ServiceContract]
    interface IService
    {
        [OperationContract]
        string HelloWorld(string strMessage);


    }
    class Program
    {
        static void Main(string[] args)
        {
            //Create instance of Binding
            WSHttpBinding myBinding = new WSHttpBinding();
            //Instance of Endpoint address
            EndpointAddress myEndpoint = new EndpointAddress("http://localhost:8090/MyService");
            //Create instance of channel factory
            ChannelFactory<IService> myChannelFactory = new ChannelFactory<IService>(myBinding, myEndpoint);
            // Create a channel.
            IService wcfClient = myChannelFactory.CreateChannel();

            string s = wcfClient.HelloWorld("Wcf");
            Console.WriteLine(s.ToString());
            ((IClientChannel)wcfClient).Close();
            Console.Read();

        }
    }
}

Click below to download complete source code

Linq to Sql: Left outer join

2010-12-17T10:13:00.000-08:00

In this post i am going to show how to generate left outer join using linq to sql. For this post i am going to use Categories and Product table of northwind.

First way to generate left outer join

var query=from p in Products
          join c in Categories
          on p.CategoryID equals c.CategoryID into pc
          where p.CategoryID==1
          from j in pc.DefaultIfEmpty()
          select new
          {
          CategoryName=j.CategoryName,
          ProductName=p.ProductName
          };

ouput generated code

SELECT [t1].[CategoryName] AS [CategoryName], [t0].[ProductName]
FROM [Products] AS [t0]
LEFT OUTER JOIN [Categories] AS [t1] ON [t0].[CategoryID] = ([t1].[CategoryID])
WHERE [t0].[CategoryID] = @p0

second way without using into operator

var query=from p in Products
          from c in Categories.Where(x=>x.CategoryID==p.CategoryID).DefaultIfEmpty()
          select new
          {
          CategoryName=c.CategoryName,
          ProductName=p.ProductName
          };

Linq to Sql:Inner join

2010-12-17T09:59:00.000-08:00

In this post i am going to show you how to generate inner join using linq to sql.
For this post i am going to use Categories and Product table of northwind.

Let's imagine that you want to fetch CategoryName and ProductName from above table using linq.

var query=from p in Products
          join c in Categories
          on p.CategoryID equals c.CategoryID
          select new
          {
          CategoryName=c.CategoryName,
          ProductName=p.ProductName
          };

Jquery and CheckboxList

2010-12-07T10:14:00.000-08:00

In this post i am going to show you how use jquery in asp.net to select the checkbox of Checkbox List

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="RadioButtonListJquery.aspx.cs"
    Inherits="RadioButtonListJquery" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <script src="Scripts/jquery-1.3.2.js" type="text/javascript"></script>
    <script type="text/javascript">
        $(document).ready(function () {
            $("#selectAll").click(function () {
                $("input[type='checkbox'").not("#selectAll").each(function () {
                    $(this).attr("checked", "true");

                });
            });
        });
    </script>
</head>
<body>
    <form id="form1" runat="server">
    <input type="button" value="Select All" id="selectAll" />
    <div id="divLanguage">
        <asp:CheckBoxList ID="chkList" runat="server">
            <asp:ListItem Text="C#" Value="1"></asp:ListItem>
            <asp:ListItem Text="Java" Value="1"></asp:ListItem>
            <asp:ListItem Text="C++" Value="1"></asp:ListItem>
            <asp:ListItem Text="C" Value="1"></asp:ListItem>
        </asp:CheckBoxList>
    </div>
    </form>
</body>
</html>

How DataContract serialize CLR object into XML

2010-12-07T09:08:00.000-08:00

In this post,I am going to show you how DataContract export DataContract into xsd ,and then how an object is converted into xml.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.Serialization;
using System.Xml.Schema;
using System.Xml;

namespace DataContract_Demo
{
    [DataContract(Namespace = "http://aspdotnetcodebook.blogspot.com", Name = "Person")]
    public class Person
    {
        [DataMember(Name = "FirstName")]
        public string FirstName { get; set; }
        [DataMember(Name = "LastName")]
        public string LastName { get; set; }
    }

    class Program
    {
        static void Main(string[] args)
        {
            GenerateXsd();
            GenerateXML();


        }

        private static void GenerateXsd()
        {

            XsdDataContractExporter exporter = new XsdDataContractExporter();
            exporter.Export(typeof(Person));
            foreach (XmlSchema xml in exporter.Schemas.Schemas("http://aspdotnetcodebook.blogspot.com"))
            {
                var writer = new XmlTextWriter(Console.Out) { Formatting = Formatting.Indented };
                xml.Write(writer);

            }
        }

        private static void GenerateXML()
        {

            var Objwriter = new XmlTextWriter(Console.Out) { Formatting = Formatting.Indented };
            var ser = new DataContractSerializer(typeof(Person));
            ser.WriteObject(Objwriter, new Person() { FirstName = "X", LastName = "Y" });
        }
    }
}

How to add a static item to a databound dropdownlist

2010-09-15T09:52:00.000-07:00

In this post i will show how to add static item to dropdownlist like a dropdown that displays one static item such as "select" while the rest of the items are data bound, then check out the code below:

Set the AppendDataBoundItems property of the dropdownlist to True, and add in the static list item. Your dropdown will look something like this:

 <asp:DropDownList ID="ddlCountry" runat="server" AppendDataBoundItems="true">
            <asp:ListItem Text="Select" Value="-1"></asp:ListItem>
        </asp:DropDownList>

check out the complete code

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default2.aspx.cs" Inherits="Default2" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:DropDownList ID="ddlCountry" runat="server" AppendDataBoundItems="true">
            <asp:ListItem Text="Select" Value="-1"></asp:ListItem>
        </asp:DropDownList>
    </div>
    </form>
</body>
</html>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class Default2 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            ddlCountry.DataSource = new Country().Get();
            ddlCountry.DataTextField = "CountryName";
            ddlCountry.DataValueField = "ID";
            ddlCountry.DataBind();
        }
    }
    public class Country
    {
        public int ID { get; set; }
        public string CountryName { get; set; }

        public List<Country> Get()
        {

            List<Country> list = new List<Country>()
            {
                new Country(){ID=1,CountryName="India"},
                new Country(){ID=2,CountryName="USA"},
                new Country(){ID=3,CountryName="UK"},
                new Country(){ID=4,CountryName="Denmark"}

            };
            return list;
        }
    }

}

How to use anonymous and Lambda expression in .net

2010-09-11T08:47:00.000-07:00

In this post I will discuss how to use anonymous and lambda expression in .net.

Imagine we have a simple example in c# that simply add two numbers.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

class Program
{
    public delegate int Fn(int a, int b);
    static void Main(string[] args)
    {
        Fn add = new Fn(Add);
        Console.WriteLine(add(1, 2));
    }
    public static int Add(int a, int b)
    {
        return (a + b);
    }
}

Let’s refactor the delegate instance version of the code to use an anonymous method.

What is anonymous method?

Anonymous methods are a new language feature in C# 2.0. Anonymous methods allow us to define a code block where a delegate object is acceptable.

Let’s convert the above code using anonymous code.

Remove the following method from the delegate instance version

        public static int Add(int a, int b)
        {
            return (a + b);
        }

And replace following code with

Fn add = new Fn(Add);

With this one.
Fn add =  delegate(int a,int b)
            {
                return (a+b);
            };

Now we can write code as shown below to use the above defined class using anonymous method as follows:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;


    class Program
    {
        public delegate int Fn(int a, int b);
        static void Main(string[] args)
        {
1.    Fn add = delegate(int a, int b)
2.    {
3.    return (a + b);
4.    };

            Console.WriteLine(add(1, 2));
        }

    }

Let’s go further and refactor our code using Lambda Expression.

What is lambda expression?

Lambda expression is inline methods that are part of the Linq technology and converted to delegates or an expression tree at compile time. Its use => operator to separate method. Meaning of => operator is goes to i.e. if you have a c# statement x=>x+y then you read this statement as x goes to x+y.

Go to the line 1 and remove the delegate keyword.

   Fn add = (int a, int b)
            {
                return (a + b);
           };
And place lambda sign => after method signature.

   Fn add = (int a, int b)=>
            {
                return (a + b);
         };

So this final lambda expression version code looks something like this.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;


    class Program
    {
        public delegate int Fn(int a, int b);
        static void Main(string[] args)
        {
            Fn add = (int a, int b) =>
            {
                return (a + b);
            };

            Console.WriteLine(add(1, 2));
        }

    }

I have summarized the above discussion into following image.