VS2005中得到 Web页面 或 窗体的 IDesignerHost

private IDesignerHost GetDesignerHost(Window window)
       {
           // In most instances, the IDesignerHost can be retrieved
           // directly off of the window object.
           IDesignerHost designerHost = window.Object as IDesignerHost;
           if (designerHost != null)
               return designerHost;

           // webform designer though, is a special case
           HTMLWindow htmlWindow = window.Object as HTMLWindow;
           if (htmlWindow != null)
           {
               // make sure current tab is the designer tab
               htmlWindow.CurrentTab = vsHTMLTabs.vsHTMLTabsDesign ;
               IOleServiceProvider oleSP = (IOleServiceProvider)htmlWindow.CurrentTabObject;
               Microsoft.VisualWebDeveloper.Interop.WebDeveloperPage.DispDesignerDocument d = htmlWindow.CurrentTabObject as Microsoft.VisualWebDeveloper.Interop.WebDeveloperPage.DispDesignerDocument;
               Guid guidVsMDDDesigner = new Guid("7494682A-37A0-11d2-A273-00C04F8EF4FF");
               IntPtr ptr;
               oleSP.QueryService(ref guidVsMDDDesigner, ref guidVsMDDDesigner, out ptr);
               if (ptr != IntPtr.Zero)
               {
                   IServiceProvider dotnetSP = (IServiceProvider)Marshal.GetObjectForIUnknown(ptr);
                   Marshal.Release(ptr);
                   designerHost = (IDesignerHost)dotnetSP.GetService(typeof(IDesignerHost));
               }
           }
           return designerHost;
       }