XTYP_ADVSTART transaction

A client uses the XTYP_ADVSTART transaction to establish an advise loop with a server. A Dynamic Data Exchange (DDE) server callback function, DdeCallback, receives this transaction when a client specifies XTYP_ADVSTART as the wType parameter of the DdeClientTransaction function.

#define     XCLASS_BOOL              0x1000
#define     XTYP_ADVSTART           (0x0030 | XCLASS_BOOL          )

Parameters

uType

The transaction type.

uFmt

The data format requested by the client.

hconv

A handle to the conversation.

hsz1

A handle to the topic name.

hsz2

A handle to the item name.

hdata

Not used.

dwData1

Not used.

dwData2

Not used.

Return value

A server callback function should return TRUE to allow an advise loop on the specified topic name and item name pair, or FALSE to deny the advise loop. If the callback function returns TRUE, any subsequent calls to the DdePostAdvise function by the server on the same topic name and item name pair causes the system to send XTYP_ADVREQ transactions to the server.

Remarks

If a client requests an advise loop on a topic name, item name, and data format for an advise loop that is already established, the Dynamic Data Exchange Management Library (DDEML) does not create a duplicate advise loop but instead alters the advise loop flags (XTYPF_ACKREQ and XTYPF_NODATA) to match the latest request.

This transaction is filtered if the server application specified the CBF_FAIL_ADVISES flag in the DdeInitialize function.

Requirements

See also

Reference

DdeClientTransaction

DdeInitialize

DdePostAdvise

Conceptual

Dynamic Data Exchange Management Library