Hi Mark,

The receiving side must create a form with a unique caption and listen for the WM_COPYDATA message. Listening means overriding the WndProc method in .NET and using BINDEVENTS() in VFP. While the application waits for messages, it must process windows messages. This means Application.Run(form) in .NET and READ EVENTS in VFP.

The sending side must search for the unique caption using FindWindow. Then it can uses this window handle to call the SendMessage() API function.

Does that make more sense?