ConnectionString in web.config (Configuration File) Asp.net

A) Add Web.Config File:-

B) adding Gridview in the form

Web.Config: file

<?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>

     <connectionStrings>

     <add name="DBCS"

     connectionString="Data Source=ITIKA-PC\SQLEXPRESS;Initial Catalog=Simple;Integrated Security=True"

     providerName="System.Data.SqlClient"/>

   

  </connectionStrings>

       <system.web>

              <compilation debug="true" targetFramework="4.0"/>

       </system.web>

</configuration>

B) Source Code:-   Soruce.cs

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Data;

using System.Data.SqlClient;

using System.Configuration;

public partial class HowtoCreateConnectionStringUsingWebconfigFile: System.Web.UI.Page

{

    protected voidPage_Load(object sender, EventArgs e)

    {

       String CS= ConfigurationManager.ConnectionStrings["DBCS"].ConnectionString;

        using (SqlConnectioncon = new SqlConnection(CS))

        {

            SqlCommand cmd = newSqlCommand("Select *from ProductTable", con);

            con.Open();

            SqlDataReader dr = cmd.ExecuteReader();

            GridView1.DataSource = dr;

            GridView1.DataBind();

        }

    }}