Hi Sai,

That is correct. Majority of controls in Infragistics.WebUI do not use that feature of WebControl. There are several reasons for that.

Rendering is performed by following call 

protected override void Render(HtmlTextWriter output)
{
 ...
 this.GetRenderer().Render(output);
}
Where GetRender() returns renderer for specific state of user machine (UpLevel or DownLevel). That renderer renders explicitly to HtmlTextWriter all tags, attributes, scripts, hidden fields, etc..

Those "renderer" classes and members are private, so, extended classes can not modify them and their logic.

Note: custom attributes are rendered by something like

System.Web.UI.AttributeCollection attrs = this.owner.Attributes;
foreach(string key in attrs.Keys)
{
 this.w(" ");
 this.w(key);
 this.w("=\"");
 this.w(attrs[key]);
 this.w("\"");
}
where w is call to output.Write...

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