Retrieves the HTML markup to display the control and populates the collection with the current control designer regions.
The design-time HTML markup for the associated control, including all control designer regions.
The design host calls the ControlDesigner.GetDesignTimeHtml(DesignerRegionCollection) method to get the design-time HTML markup and the current list of control designer regions. Using the DesignerRegionCollection, the design host can then request the markup for each editable control designer region.
The ControlDesigner.GetDesignTimeHtml(DesignerRegionCollection) method is provided for a derived control designer, such as the System.Web.UI.Design.WebControls.GridViewDesigner class, that must process the content for the region before calling the ControlDesigner.GetDesignTimeHtml method.