Manages the concurrency required by the interaction of OLE applications.
The COleMessageFilter class is useful in visual editing server and container applications, as well as OLE automation applications. For server applications that are being called, this class can be used to make the application "busy" so that incoming calls from other container applications are either canceled or retried later. This class can also be used to determine the action to be taken by a calling application when the called application is busy.
Common usage is for a server application to call BeginBusyState and EndBusyState when it would be dangerous for a document or other OLE accessible object to be destroyed. These calls are made in CWinApp::OnIdle during user-interface updates.
By default, a COleMessageFilter object is allocated when the application is initialized. It can be retrieved with AfxOleGetMessageFilter.
This is an advanced class; you seldom need to work with it directly.
For more information, see the article Servers: Implementing a Server.