At design time, the GetRunTimeHtml() method of the DynamicImageDesigner can use the DesignTimeRenderInternal method to return design time html without modifying ImageUrl. (If the GetRunTimeHtml function is not implemented, then the designer will call Render() on the control to get the design-time HTML; we want to prevent this from happening, since Render() causes the ImageUrl property to be modified.
[Visual Basic] Overrides Protected Sub DesignTimeRenderInternal( _ ByVal writer As HtmlTextWriter _ ) [C#] protected override void DesignTimeRenderInternal( HtmlTextWriter writer ); [C++] protected: override void DesignTimeRenderInternal( HtmlTextWriter* writer ); [JScript] protected override function DesignTimeRenderInternal( writer : HtmlTextWriter );
DynamicImage Class | DynamicImage Members | System.Web.UI.WebControls Namespace