Get all checkbox checked in gridview/repeater/datalist

Following is the simplest way to get checked checkbox in a grid:

<asp:GridView runat="server" ID="grd" AutoGenerateColumns="false">

  <EmptyDataTemplate>

    No data found

  </EmptyDataTemplate>

  <Columns>

    <asp:TemplateField HeaderStyle-Width="4%">

      <HeaderTemplate>

        <input type="checkbox" id="cbUserAll" title="Select/Unselect All" onclick="SelectAllCB('ckbUser', this);" />

      </HeaderTemplate>

      <ItemTemplate>

        <input type="checkbox" id='ckbUser<%#Eval("Id")%>' name="ckbUser" value='<%#Eval("Id")%>' />

      </ItemTemplate>

In CS page:

  string str = Convert.ToString(Request.Form["ckbuser"]);

This will get all selected checkbox values comma separated.