Many of the data exchange functions and subroutines accept a status argument that is bundled by the DDE DLL with the Windows message when it is delivered to the partner application. The DDE protocol prescribes the valid status values for each message, and what they mean. The ESL DDE DLL generates an error event if the status used for a given subroutine or function is not valid for the DDE message. When this happens, the message is not sent. A single status variable can encode multiple status flags. The following functions are used for setting and querying the individual flags in a status variable:
See The ESL DDE Functions and Subroutines for a complete description of each of these functions. You can use these functions to construct an appropriate status parameter, or to decompose a status value received from a partner (through the DDEGetStatus call). The valid status flag values (defined in ESLDDE.INC) are as follows:
Status Flag Value |
Description |
A positive acknowledgment. |
|
Partner was busy. (Only valid if flag is not set.) |
|
Send subsequent DATA messages with zero-length data portion (for DDE_ADVISE). |
|
Request acknowledgment. |
|
Data is sent in response to a DDE_REQUEST. |
|
Data not processed. (This is valid only if the DDE_FACK flag is not set.) |
