Delete checked Rows in Gridview

Step 1: Create aspx page like that :-

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="CheckBoxinGriedview.aspx.cs"

    Inherits="WebApplication1.WebForm5" %>

<!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">

        var TotalChkBx;

        var Counter;

        window.onload = function () {

            //Get total no. of CheckBoxes in side the GridView.

            TotalChkBx = parseInt('<%= this.gvCheckboxes.Rows.Count %>');

            //Get total no. of checked CheckBoxes in side the GridView.

            Counter = 0;

        }

        function HeaderClick(CheckBox) {

            //Get target base & child control.

            var TargetBaseControl =

       document.getElementById('<%= this.gvCheckboxes.ClientID %>');

            var TargetChildControl = "chkBxSelect";

            //Get all the control of the type INPUT in the base control.

            var Inputs = TargetBaseControl.getElementsByTagName("input");

            //Checked/Unchecked all the checkBoxes in side the GridView.

            for (var n = 0; n < Inputs.length; ++n)

                if (Inputs[n].type == 'checkbox' &&

                Inputs[n].id.indexOf(TargetChildControl, 0) >= 0)

                    Inputs[n].checked = CheckBox.checked;

            //Reset Counter

            Counter = CheckBox.checked ? TotalChkBx : 0;

        }

        function ChildClick(CheckBox, HCheckBox) {

            //get target control.

            var HeaderCheckBox = document.getElementById(HCheckBox);

            //Modifiy Counter; 

            if (CheckBox.checked && Counter < TotalChkBx)

                Counter++;

            else if (Counter > 0)

                Counter--;

            //Change state of the header CheckBox.

            if (Counter < TotalChkBx)

                HeaderCheckBox.checked = false;

            else if (Counter == TotalChkBx)

                HeaderCheckBox.checked = true;

        }

    </script>

</head>

<body>

    <form id="form1" runat="server">

    <div>

        <asp:GridView ID="gvCheckboxes" runat="server" AutoGenerateColumns="False" DataKeyNames="id"

            DataSourceID="SqlDataSource1" OnRowCreated="gvCheckboxes_RowCreated" OnRowDataBound="gvCheckboxes_RowDataBound">

            <Columns>

                <asp:TemplateField>

                    <ItemTemplate>

                        <asp:CheckBox ID="chkBxSelect" runat="server" />

                    </ItemTemplate>

                    <HeaderTemplate>

                        <asp:CheckBox ID="chkBxHeader" onclick="javascript:HeaderClick(this);" runat="server" />

                    </HeaderTemplate>

                </asp:TemplateField>

                <asp:BoundField HeaderText="id" DataField="id" SortExpression="id" InsertVisible="False"

                    ReadOnly="True" />

                <asp:BoundField DataField="article" HeaderText="article" SortExpression="article" />

            </Columns>

        </asp:GridView>

        <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:DemoConnectionString %>"

            SelectCommand="SELECT * FROM [blog]" 

            DeleteCommand="DELETE FROM [blog] WHERE [id] = @id" 

            InsertCommand="INSERT INTO [blog] ([article]) VALUES (@article)" 

            UpdateCommand="UPDATE [blog] SET [article] = @article WHERE [id] = @id">

            <DeleteParameters>

                <asp:Parameter Name="id" Type="Int32" />

            </DeleteParameters>

            <InsertParameters>

                <asp:Parameter Name="article" Type="String" />

            </InsertParameters>

            <UpdateParameters>

                <asp:Parameter Name="article" Type="String" />

                <asp:Parameter Name="id" Type="Int32" />

            </UpdateParameters>

        </asp:SqlDataSource>

        <asp:Button ID="Button1" runat="server" Text="Delete" OnClick="Button1_Click" />

    </div>

    </form>

</body>

</html>

Step 2: Copy the following code in code behind :-

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.IO;

using System.Text;

using System.Data;

using System.Data.SqlClient;

using System.Configuration;

namespace WebApplication1

{

    public partial class WebForm5 : System.Web.UI.Page

    {

        string strConnection = ConfigurationManager.ConnectionStrings["DemoConnectionString"].ConnectionString;

        protected void Page_Load(object sender, EventArgs e)

        {

            

        }

 protected void Button1_Click(object sender, EventArgs e)
        {
            //StringBuilder str = new StringBuilder();

            // Select the checkboxes from the GridView control

            for (int i = 0; i < gvCheckboxes.Rows.Count; i++)
            {
                GridViewRow row = gvCheckboxes.Rows[i];
                bool isChecked = ((CheckBox)row.FindControl("chkBxSelect")).Checked;

                if (isChecked)
                {
                    // Column 2 is the name column
                    //str.Append(gvCheckboxes.Rows[i].Cells[1].Text + "<br>");
                    int employeeID = Convert.ToInt32(gvCheckboxes.DataKeys[row.RowIndex].Value);
                    // Pass the value of the selected Employye ID to the Delete //command.
                    //SqlDataSource1.DeleteParameters["id"].DefaultValue = employeeID.ToString();
                    //SqlDataSource1.Delete();
                    DeleteMultipleRecords(employeeID);
                 }
            }
            gvCheckboxes.DataBind();

            // prints out the result
            //Response.Write(str.ToString());
    }
        public void DeleteMultipleRecords(int id)
        {
            string cmd = "Delete blog where id=@Id";
            SqlConnection mycon = new SqlConnection(strConnection);
            SqlCommand mycmd = new SqlCommand(cmd, mycon);
            mycmd.Parameters.Add("@id", SqlDbType.Int).Value = id;
            mycon.Open();
            mycmd.ExecuteNonQuery();

        }

        protected void gvCheckboxes_RowDataBound(object sender, GridViewRowEventArgs e)

        {

            

                e.Row.Cells[1].Visible = false;

           

            if (e.Row.RowType == DataControlRowType.DataRow)

            {

                CheckBox chkBxSelect = (CheckBox)e.Row.Cells[0].FindControl("chkBxSelect");

                CheckBox chkBxHeader = (CheckBox)this.gvCheckboxes.HeaderRow.FindControl("chkBxHeader");

                chkBxSelect.Attributes["onclick"] = string.Format("javascript:ChildClick(this,'{0}');",chkBxHeader.ClientID);

            }

        }

        protected void gvCheckboxes_RowCreated(object sender, GridViewRowEventArgs e)

        {

            

        }

    }

}