ISpNotifyTranslator::InitCallback
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8/28/2008
This method sets up an ISpNotifyTranslator object to send notifications using a standard C-style callback function.
Syntax
HRESULT InitCallback(
SPNOTIFYCALLBACK* pfnCallback,
WPARAM wParam,
LPARAM lParam
);
Parameters
- pfnCallback
[in] Pointer to the notification callback function to use.
- wParam
[in] Constant WPARAM value to pass to notification callback function when it is called.
- lParam
[in] Constant LPARAM value to pass to the notification callback function when it is called.
Return Value
The following table shows the possible return values.
| Value | Description |
|---|---|
S_OK |
Function completed successfully. |
SPERR_ALREADY_INITIALIZED |
SpTranslator object is already initialized. |
E_INVALIDARG |
pfnCallback is invalid or bad. |
FAILED(hr) |
Appropriate error message. |
Remarks
The translator implementation uses a hidden window to call back the client on the same thread that was used to initialize the event source. Notification callbacks are the result of processing a window message. When this notification mechanism is used:
The SPNOTIFYCALLBACK method will always be called on the thread that initialized the event source or notify translator object.
The thread must have a window message pump.
The SPNOTIFYCALLBACK function is declared as follows:
typedef void __stdcall SPNOTIFYCALLBACK(WPARAM wParam, LPARAM lParam);
Requirements
| Header | sapi.h, sapi.idl |
| Library | sapilib.lib |
| Windows Embedded CE | Windows CE .NET 4.1 and later |