Check/Uncheck All Checkboxes in Asp.Net Gridview

Introduction:

In this article we will see how to check and uncheck all CheckBoxes present in an ASP.Net GridView control.

Background:

While programming many times we need to use a CheckBox control in an ASP.Net GridView for allowing selection of a particular row of a GridView. In some cases a GridView can contain 100 of records and if the user wants to select all rows of the GridView then selecting each row one by one is very tedious and a time-consuming job. To make it easier we will see how to write a simple method for selecting all CheckBoxes in a GridView. Take a look at the following snippets.

1. Create a new website. On the default.aspx page keep the GridView control with AutogeneratedColumn = false. The source for the GridView should look like below.
   
   asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False">
           <Columns>
           <asp:TemplateField ShowHeader="false">
          <ItemTemplate>
          <asp:CheckBox ID="chkid" runat="server" />
           </ItemTemplate>
          </asp:TemplateField>
           <asp:BoundField DataField="Auth_Name" HeaderText="Author Name" />
           <asp:BoundField DataField="Auth_Loc" HeaderText="Location" />
           </Columns>
           </asp:GridView>
    
2. Keep two buttons on the form; one for checking all checkboxes and the other for unchecking.
    
3. The CheckState method is for performing a check/uncheck operation in the GridView. This method will take true/false as input to check/uncheck the checkboxes of the GridView.
   
   private void CheckState(bool p)
       {

           foreach (GridViewRow row in GridView1.Rows)
          {
              CheckBox chkcheck = (CheckBox)row.FindControl("chkid");
                    chkcheck.Checked = p;
           }
       }
    

4. Bind your GridView and run.

Conclusion:

By using a simple method we are able to check/uncheck 100 of rows also in GridView.