Refreshes the design-time HTML markup for the associated Web server control by calling the erload:System.Web.UI.Design.ControlDesigner.GetDesignTimeHtml method.
The ControlDesigner.UpdateDesignTimeHtml method is called by the design host to update the display of the associated Web server control at design time, such as when the control has been modified. Also, a control designer can call the ControlDesigner.UpdateDesignTimeHtml method after modifying values of the control to update the display of the control.
If you are calling the System.ComponentModel.Design.IComponentChangeService.ComponentChanged event, or using the System.ComponentModel.PropertyDescriptor object to set properties, the System.ComponentModel.Design.IComponentChangeService interface calls the ControlDesigner.UpdateDesignTimeHtml method for you.