OBSOLETE - How to create an Advanced Selection CheckBox at runtime

UPDATED:

Starting with version v2014 vol 1 (v14.1), this functionality is available out of the box. Simply set the GridViewCommandColumn.SelectAllCheckboxMode property to GridViewSelectAllCheckBoxMode.AllPages to activate it. Please refer to the ASP.NET: GridView Select All Rows Updated blog post and the Select All Rows demo for more information.

If you have version v14.1+ available, consider using the built-in functionality instead of the approach detailed below.
If you need further clarification, create a new ticket in our Support Center.

This sample demonstrates how to create an advanced selection checkbox at runtime. To implement this, I have created a new class (CommandColumnHeaderTemplate). This class implements the ITemplate interface and contains the code to create the CheckBox shown in the CommandColumn's header.