The aspx page

<asp:TemplateField>
   <ItemTemplate>
     <asp:LinkButton ID="btnTemplate" runat="server" OnClick="btnTemplate_Click">LinkButton</asp:LinkButton>
   </ItemTemplate>
</asp:TemplateField>

 

The C# code behind

protected void btnTemplate_Click(object sender, EventArgs e)
   {
       //Clear Selection
       GridView1.SelectedIndex = -1;

       // Get the checkbox that was Selected
       LinkButton btnTemplate = (LinkButton)sender;

       // As this is a template column, we can get the specifc row by using the Naming Container
       GridViewRow selectedGridRow = (GridViewRow)btnTemplate.NamingContainer;

       // get the userID from the first column that is hidden by CSS
       Response.Write(selectedGridRow.Cells[0].Text);
   }

ddEvents.Items.Insert(0, (new ListItem("Select Event...", "0")));