WM_DDE_ADVISE

This message (posted by a client application) requests the receiving application to supply an update for a data item whenever it changes. This message is always posted.

Syntax

param1
HWND hwnd;          /* Window handle of the sender. */

param2
PDDESTRUCT pDdeStruct; /* DDE structure. */

Parameters

hwnd (HWND) - input

Window handle of the sender.

pDdeStruct (PDDESTRUCT) - input

DDE structure.

This points to a dynamic data exchange structure. See DDESTRUCT.

Flags in the fsStatus field are set as follows:

DDE_FACKREQ: If this bit is 1, the receiving (server) application is requested

to send its WM_DDE_DATA messages with the acknowledgment-requested (DDE_FACKREQ)

bit set. This offers a flow control technique, whereby the client application

can avoid overload from incoming WM_DDE_DATA messages.

DDE_FNODATA: If this bit is 1, the server is requested to send its WM_DDE_DATA

messages with a zero length data portion. These messages are alarms that tell the

client the source data has changed. Upon receiving one of these alarms, the client

can choose to call for the latest version of the data by issuing a WM_DDE_REQUEST

message, or the client can choose to ignore the alarm. This is typically used when

there is a significant resource cost associated with actually rendering and/or

assimilating the data.

offszItemName identifies which data item is being requested.

usFormat is the preferred type of data of the client. It must be a

registered DDE data format number.

Returns

ulReserved (ULONG) - return

Reserved value, should be 0.

Remarks

The receiving application is expected to reply with a positive WM_DDE_ACK message if it can provide the requested data, or with a negative one if it can not.

Default Processing

None.