PRB: Some OLE Containers Do Not Call IViewObject::Draw

• Microsoft Win32 Software Development Kit (SDK) for Windows NT version 3.5
• Microsoft OLE Libraries for Windows and Win32s, version 2.01
• Microsoft OLE Libraries included with:

      - Microsoft Windows NT version 3.5
      - Microsoft Windows 95
  

SYMPTOMS

A custom OLE rendering handler finds that its IViewObject::Draw method is never called by some OLE container applications.

CAUSE

Some OLE container applications never call IViewObject::Draw. These applications do not use the caching and drawing services provided by the object handler. Instead, they do their own caching and drawing of the presentations for OLE objects embedded in their documents.

Two examples of such container applications are Microsoft Word version 6.0 and Microsoft Excel version 5.0. They cache metafile representations of embedded OLE objects, and then do their own drawing of those metafiles.

STATUS

This behavior is by design. It is not possible to get Microsoft Word or Microsoft Excel to use a handler's drawing services.