updating multiple records using gridview

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





   


   

   

                                 AllowPaging="True"
                             DataSourceID="SqlDataSource1"
                             AutoGenerateColumns="false">

 
    
 
   
   
                      AutoPostBack="true"
             OnCheckedChanged="chkSelect_CheckedChanged"/>
   
   
   
                                       SortExpression="ID"/>
                                  
                           SortExpression="Name">
   
                     Text='<%# Bind("Name") %>' ReadOnly="true"
                 ForeColor="Blue" BorderStyle="none"
                 BorderWidth="0px" >
   
   
   
   
                           SortExpression="Location">
   
                     Text='<%# Bind("Location") %>'
                 ReadOnly="true" ForeColor="Blue"
                 BorderStyle="none" BorderWidth="0px">
   
   
   



ConnectionString="<%$ ConnectionStrings:ConnectionString %>"
SelectCommand="SELECT [ID], [Name], [Location] FROM [Details]"
DeleteCommand="DELETE FROM Details WHERE (ID = @ID)"
UpdateCommand="UPDATE [Details] SET [Name] = @Name,
              [Location] = @Location WHERE [ID] = @ID">
       
            
       
       
               
               
               
       
       

       
            OnClick="btnUpdate_Click" Text="Update" />

           

   

            Text="Check all" />
            Text="UnCheck all" />
   











using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Data.SqlClient;
using System.Text;
namespace Editable_GridView_multiple_records
{
    public partial class _Default : System.Web.UI.Page
    {
        string connStr = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;

        protected void btnUpdate_Click(object sender, EventArgs e)
        {
            StringBuilder strSql = new StringBuilder(string.Empty);

            SqlConnection con = new SqlConnection(connStr);
            SqlCommand cmd = new SqlCommand();

            for (int i = 0; i < GridView1.Rows.Count; i++)
            {
                CheckBox chkUpdate = (CheckBox)
                   GridView1.Rows[i].Cells[0].FindControl("chkSelect");
                if (chkUpdate != null)
                {
                    if (chkUpdate.Checked)
                    {

                        string strID = GridView1.Rows[i].Cells[1].Text;
                        string strName = ((TextBox)
                            GridView1.Rows[i].FindControl("txtName")).Text;

                        string strLocation = ((TextBox)
                            GridView1.Rows[i].FindControl("txtLocation")).Text;

                        string strUpdate =
                            "Update Details set Name = '" + strName + "',Location = '" + strLocation + "' WHERE ID ='" + strID + "'";

                        strSql.Append(strUpdate);
                    }
                }
            }
            try
            {
                cmd.CommandType = CommandType.Text;
                cmd.CommandText = strSql.ToString();
                cmd.Connection = con;
                con.Open();
                cmd.ExecuteNonQuery();
            }
            catch (SqlException ex)
            {
                string errorMsg = "Error in Updation";
                errorMsg += ex.Message;
                throw new Exception(errorMsg);
            }
            finally
            {
                con.Close();
            }
            UncheckAll();
        }
        private void UncheckAll()
        {
            foreach (GridViewRow row in GridView1.Rows)
            {
                CheckBox chkUncheck = (CheckBox)
                             row.FindControl("chkSelect");
                TextBox txtname = (TextBox)
                               row.FindControl("txtName");
                TextBox txtlocation = (TextBox)
                           row.FindControl("txtLocation");
                chkUncheck.Checked = false;
                txtname.ReadOnly = true;
                txtlocation.ReadOnly = true;
                txtname.ForeColor = System.Drawing.Color.Blue;
                txtlocation.ForeColor = System.Drawing.Color.Blue;
            }
        }
        protected void chkSelect_CheckedChanged
                            (object sender, EventArgs e)
        {
            CheckBox chkTest = (CheckBox)sender;
            GridViewRow grdRow = (GridViewRow)chkTest.NamingContainer;
            TextBox txtname = (TextBox)grdRow.FindControl
                                                ("txtName");
            TextBox txtlocation = (TextBox)grdRow.FindControl
                                              ("txtLocation");
            if (chkTest.Checked)
            {
                txtname.ReadOnly = false;
                txtlocation.ReadOnly = false;
                txtname.ForeColor = System.Drawing.Color.Black;
                txtlocation.ForeColor = System.Drawing.Color.Black;
            }
            else
            {
                txtname.ReadOnly = true;
                txtlocation.ReadOnly = true;
                txtname.ForeColor = System.Drawing.Color.Blue;
                txtlocation.ForeColor = System.Drawing.Color.Blue;
            }
        }

        protected void Button1_Click(object sender, EventArgs e)
        {
            CheckState(true);
        }

        protected void Button2_Click(object sender, EventArgs e)
        {
            CheckState(false);
        }
        private void CheckState(bool p)
        {

            foreach (GridViewRow row in GridView1.Rows)
            {
                CheckBox chkcheck = (CheckBox)row.FindControl("chkSelect");

                chkcheck.Checked = p;

            }

        }
    }
}