As with any other designer, override the GetEmptyDesignTimeHtml. Gets the HTML used to represent an empty template-based control at design time.
[Visual Basic] Overrides Protected Function () As String [C#] protected override string (); [C++] protected: String* (); [JScript] protected override function (): String;
DesktopPanesDesigner Class | DUEMETRI.UI.Design.WebControls Namespace