GetWndMessageFilter is called once by the UFT infrastructure at the initialization of the object. The Custom object receives window messages according to the returned filtering level. The default implementation returns WND_MSGS.
Receiving window messages prevents UFT from handling them. For example, if CHILD_MSGS is returned, UFT will not receive messages for child windows, and therefore will not create Test Objects for them. You can, however, change this behavior by passing messages back to UFT. To pass messages on, override CustomServerBase.OnMessage to return a value other than RECORD_HANDLED. Otherwise, UFT will not handle these messages, and you should override
OnMessage in your Custom Server to handle them.