How to add checkbox to GridView rows in C#?

You must have seen many applications where the GridView provides controls like Checkboxes, Buttons, Textboxes etc. for user activities. This article focuses on how to add a checkbox to a GridView control and how to perform joint operations over a set of selected rows from the GridView, like deleting multiple rows selected by the user.

GridView in Asp.Net is a data control which is used to display data in a tabular manner. Data GridView control are capable of displaying not only data but also some visual elements like checkbox, combobox, textbox, buttons etc.

Here we will see how to add a checkbox to GridView. To add any visual control to a GridView we will have to use Styles or Templates. I would demonstrate the insertion of a CheckBox in a GridView through a small web application where we will bind the data from an SQL data table to a Gridview. We would add the checkbox to the GridView by using the Template field. After the GridView gets populated we would select multiple rows through the check boxes and delete all the selected rows together on a single click.

First create a web application from Visual Studio as File>New>Project. Select Visual C#>Web then Asp.Net Empty web application.

Now add a GridView control to your web application and bind this GridView control to the required data table by initializing a connection to the database. In order to create and use an SQL connection we would require to add the following namespaces in our program:

using System.Data;
using System.Data.SqlClient; 

Source code for Adding CheckBox to GridView

<asp:GridView ID="gvw_employees" runat="server" AutoGenerateColumns="False">
<Columns>
   <asp:BoundField Datafield ="emp_id_pk" HeaderText ="Employee ID"/>
   <asp:BoundField Datafield ="emp_fullname" HeaderText ="Employee Full Name"/>
   <asp:BoundField Datafield ="emp_designation" HeaderText ="Designation"/>
   <asp:BoundField Datafield ="emp_department" HeaderText ="Department"/>

   <%-- Adding CheckBox to Grid View --%>
   <asp:TemplateField HeaderText ="Select">
   	<ItemTemplate>
           <asp:CheckBox ID ="checkBox" runat="server" />
       </ItemTemplate>
    </asp:TemplateField>
  </Columns>
</asp:GridView>

C# code for adding CheckBox to a GridView

public partial class WebForm1 : System.Web.UI.Page
    {
        SqlConnection conn = new SqlConnection();
        SqlCommand cmd = new SqlCommand();
        SqlCommandBuilder cb = new SqlCommandBuilder();
        SqlDataAdapter adp = new SqlDataAdapter();
        DataSet ds = new DataSet();
        DataRow dr;

        protected void Page_Load(object sender, EventArgs e)
        {
           conn.ConnectionString = "Connection string"; // Put actual conn string here
           cmd.Connection = conn;
           adp.SelectCommand = cmd;

            //Binding the Grid to the database table
            if (!IsPostBack)
            {
                cmd.CommandText = "select * from EmpDetails";
                adp.Fill(ds, "st");
                gvw_employees.DataSource = ds.Tables["st"];
                gvw_employees.DataBind();
            }
            
        }

C# code for deleting multiple selected rows from a GridView