A DDE server callback function receives this transaction when a client specifies XTYP_REQUEST as the wType parameter of the DdeClientTransaction function. A client uses this transaction to request data from a server.
wFmt
Specifies the format in which the server should submit data to the client.
hConv
Identifies the conversation.
hsz1
Identifies the topic name.
hsz2
Identifies the item name that has changed.
hData
Not used.
dwData1
Not used.
dwData2
Not used.
The server should call the DdeCreateDataHandle function to create a data handle that identifies the changed data, then return the handle. The server should return NULL if it is unable to complete the transaction. If the server returns NULL, the client will receive a DDE_FNOTPROCESSED acknowledgment flag.
This transaction is filtered if the server application specified the CBF_FAIL_REQUESTS flag in the DdeInitialize function.
If responding to this transaction requires lengthy processing, the server can return CBR_BLOCK to suspend future transactions on the current conversation, then process the transaction asynchronously. When the server has finished and the data is ready to pass to the client, the server can call the DdeEnableCallback function to resume the conversation.
DdeClientTransaction, DdeCreateDataHandle, DdeEnableCallback, DdeInitialize