Forms Data Controls :: Behind Code C# Create Gridview?

I now need to create a Gridview using C# code behind and using PlaceHolder to render in ASPX page. So far everything is Okey, pager and data inside database also can pull out to gridview. But the problem is no sorting function here, below is my code. GridViewTemplate .cs this class is for add data into Gridview ItemTemplate and HeaderTemplate, I modify from here http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.templatefield.templatefield.aspx

public class GridViewTemplate : ITemplate
{
private DataControlRowType templateType;

[code]...