XTYP_UNREGISTER transaction

A Dynamic Data Exchange (DDE) callback function, DdeCallback, 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.

#define     XCLASS_NOTIFICATION      0x8000
#define     XTYPF_NOBLOCK            0x0002
#define     XTYP_UNREGISTER         (0x00D0 | XCLASS_NOTIFICATION | XTYPF_NOBLOCK)

Parameters

uType

The transaction type.

uFmt

Not used.

hconv

Not used.

hsz1

A handle to the base service name being unregistered.

hsz2

A handle to the instance-specific service name being unregistered.

hdata

Not used.

dwData1

Not used.

dwData2

Not used.

Remarks

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.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Header	Ddeml.h (include Windows.h)

See also

Reference

DdeInitialize

DdeNameService

Conceptual

Dynamic Data Exchange Management Library