XTYP_WILDCONNECT transaction

Enables a client to establish a conversation on each of the server's service name and topic name pairs that match the specified service name and topic name. A Dynamic Data Exchange (DDE) server callback function, DdeCallback, receives this transaction when a client specifies a NULL service name, a NULL topic name, or both in a call to the DdeConnect or DdeConnectList function.


#define     XCLASS_DATA              0x2000
#define     XTYPF_NOBLOCK            0x0002
#define     XTYP_WILDCONNECT        (0x00E0 | XCLASS_DATA | XTYPF_NOBLOCK)

Parameters

uType

The transaction type.

uFmt

Not used.

hconv

Not used.

hsz1

A handle to the topic name. If this parameter is NULL, the client is requesting a conversation on all topic names that the server supports.

hsz2

A handle to the service name. If this parameter is NULL, the client is requesting a conversation on all service names that the server supports.

hdata

Not used.

dwData1

A pointer to a CONVCONTEXT structure that contains context information for the conversation. If the client is not a DDEML application, this parameter is set to 0.

dwData2

Specifies whether the client is the same application instance as the server. If the parameter is 1, the client is same instance. If the parameter is 0, the client is a different instance.

Return value

The server should return a data handle that identifies an array of HSZPAIR structures. The array should contain one structure for each service-name and topic-name pair that matches the service-name and topic-name pair requested by the client. The array must be terminated by a NULL string handle. The system sends the XTYP_CONNECT_CONFIRM transaction to the server to confirm each conversation and to pass the conversation handles to the server. The server will not receive these confirmations if it specified the CBF_SKIP_CONNECT_CONFIRMS flag in the DdeInitialize function.

The server should return NULL to refuse the XTYP_WILDCONNECT transaction.

Remarks

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

A server cannot block this transaction type; the CBR_BLOCK return code is ignored.

Requirements

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
CONVCONTEXT
DdeConnect
DdeInitialize
HSZPAIR
Conceptual
Dynamic Data Exchange Management Library

 

 

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