XTYP_UNREGISTER
A dynamic data exchange (DDE) callback function receives the XTYP_UNREGISTER transaction whenever a Dynamic Data Exchange Management Library (DDEML) server application uses the DdeNameService function to unregister a service name, or whenever a non-DDEML application that supports the System topic is terminated.
This transaction is filtered if the application specified the CBF_SKIP_REGISTRATIONS flag in the DdeInitialize function.
A application cannot block this transaction type; the CBR_BLOCK return code is ignored.
An application should use the hsz1 parameter to remove the service name from the list of servers available to the user. An application should use the hsz2 parameter to identify which application instance has terminated.
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Unsupported.
Header: Declared in ddeml.h.
Dynamic Data Exchange Management Library Overview, Dynamic Data Exchange Management Transactions, DdeInitialize, DdeNameService