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
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uType
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The transaction type.
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uFmt
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Not used.
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hconv
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Not used.
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hsz1
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A handle to the base service name being unregistered.
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hsz2
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A handle to the instance-specific service name being unregistered.
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hdata
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Not used.
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dwData1
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Not used.
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dwData2
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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 |
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See also
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Reference
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Conceptual