ISpNotifyTranslator::InitCallback (SAPI 5.4)
ISpNotifyTranslator::InitCallback sets up this instance to send notifications using a standard C-style callback function.
HRESULT InitCallback( SPNOTIFYCALLBACK *pfnCallback, WPARAM wParam, LPARAM lParam );
- [in] The notification callback function to be used.
- [in] Constant WPARAM value that will be passed to the pfnCallback function when it is called.
- [in] Constant LPARAM value that will be passed to the pfnCallback function when it is called.
|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.|
The translator implementation uses a hidden window to call back the client on the same thread that was used to initialize the event source. Notify 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);