Return Parameters
This function returns a data string and a return code.
- Data String:
- If A (asynchronous mode of notification) is specified in position 5 and the function is completed successfully, the following data string is returned:
| Byte | Definition | |
|---|---|---|
| Standard | Enhanced | |
| 1 | 1 | A 1-character presentation space short name (PSID). |
| 2–8 | Reserved. | |
| 9–12 | 4-byte value in which the event object address is returned by EHLLAPI. The application can wait for this event object (32-bit only). | |
- Data String:
- If M (asynchronous message mode) is specified in position 5 (2 for standard interface) and the function is completed successfully, the following data string is returned:
| Byte | Definition | |
|---|---|---|
| Standard | Enhanced | |
| 1 | 1 | A 1-character presentation space short name (PSID) |
| 2–8 | Reserved | |
| 3–4 | 9–10 | Task ID of asynchronous message mode |
Note:
If OIA or presentation space is updated, an application
window receives a message. The message is a return value of RegisterWindowMessage
(PCSHLL). The wParam parameter contains the Task ID returned by the
function call. HIWORD of lParam contains Return Code 21 (shows the
OIA is updated), 22 (shows the host presentation space is updated),
or 23 (shows both the OIA and the host presentation space are updated),
and LOWORD of lParam parameter contains function number 23.
- Return Code:
- The following codes are defined:
| Return Code | Definition |
|---|---|
| 0 | The Start Host Notification function was successful. |
| 1 | An incorrect host presentation space was specified. |
| 2 | An error was made in designating parameters. |
| 9 | A system error was encountered. |