ISpRecoGrammar::SetDictationState
ISpRecoGrammar::SetDictationState sets the dictation topic state.
The dictation topic is specified by calling ISpRecoGrammar::LoadDictation.
HRESULT SetDictationState(
SPRULESTATE NewState
);
Parameters
- NewState
- [in] Flag of type SPRULESTATE indicating the new state of dictation. See Remarks section
Return values
| Value | Description |
|---|---|
| S_OK | Function completed successfully. |
| E_INVALIDARG | NewState is not an acceptable value. |
| SP_STREAM_UNINITIALIZED | ISpRecognizer::SetInput has not been called with the InProc SR engine |
| SPERR_UNINITIALIZED | A dictation is not currently loaded. |
| SPERR_UNSUPPORTED_FORMAT | Audio format is bad or is not recognized. Alternatively, the device driver may be busy by another application and cannot be accessed. |
| FAILED(hr) | Appropriate error message. |
Remarks
An application can use the SPRS_ACTIVE_WITH_AUTO_PAUSE state to pause the engine after each dictation recognition is sent. The application must reactivate the SR engine (see ISpRecoContext::Resume) to prevent the loss of input audio data (see SPERR_AUDIO_BUFFER_OVERFLOW).
By default, the recognizer state (SPRECOSTATE) is SPRST_ACTIVE, which means that recognition will begin as soon as dictation is activated. Consequently, an application should not activate the dictation state until it is prepared to receive recognitions. An application can also disable the SpRecoContext object (see ISpRecoContext::SetContextState) or SpRecoGrammar objects (see ISpRecoGrammar::SetGrammarState) to prevent recognitions from being fired for active dictation topics.
If the recognizer state is SPRST_ACTIVE, SAPI will first attempt to open the audio input stream when dictation (or a rule) is activated. Consequently, if the audio device is already in use by another application, or the stream fails to open, the failure code will be returned using ::SetDictationState. The application should handle this failure gracefully.
If an application uses an InProc recognizer, it must call ISpRecognizer::SetInput with a non-NULL setting before the recognizer will return recognitions, regardless of the dictation topic state.
Example
The following code snippet illustrates the use of ISpRecoGrammar::SetDictationState to load a spelling topic and activate it.
// Declare local identifiers:
HRESULT hr = S_OK;
CComPtr<ISpRecoGrammar> cpRecoGrammar;
CComPtr<ISpRecoContext> cpRecoContext;
ULONGLONG ullGramId = 1;
// Create a grammar object.
hr = cpRecoContext->CreateGrammar(ullGramId, &cpRecoGrammar;);
if (SUCCEEDED(hr))
{
// Load the general dictation topic.
hr = cpRecoGrammar->LoadDictation(NULL, SPLO_STATIC);
}
if (SUCCEEDED(hr))
{
// Activate the dictation topic to receive recognitions.
hr = cpRecoGrammar->SetDictationState(SPRS_ACTIVE);
}
if (SUCCEEDED(hr))
{
// Do stuff here.
}