SpeechRecognitionEngine.RecognizeAsync Method ()

Provides a single asynchronous recognition operation on recognition engine input.

Namespace: Microsoft.Speech.Recognition
Assembly: Microsoft.Speech (in microsoft.speech.dll)

Syntax

Remarks

RecognizeAsync performs a single recognition operation, and then terminates.

The results of asynchronous recognition operations are obtained by event handlers, in particular RecognizeCompleted, SpeechRecognitionRejected, and SpeechRecognized.

If recognition has been successful, the Result property on the instance of RecognizeCompletedEventArgs passed to the RecognizeCompleted handler will not be null.

Recognition failure may be due either to time out, or by a failure of the recognition engine grammar. Time out values are set by BabbleTimeout and InitialSilenceTimeout of the current instance of SpeechRecognitionEngine.

Example

In the following example show the implementation of a start/stop button for a application with a graphical user interface using SpeechRecognitionEngine. Depending on the state of the application, when the button is clicked RecognizeAsync is called with either Single or

private void _startRecogButton_Click(object sender, EventArgs eventArgs) {
    if (_startRecogButton.Text == "Start Speech Recognition") { //Toggle Speech Recogniztion on
        _startRecogButton.Text = "Stop Speech Recognition";
        if (_useMultiple) {
            _recognitionEngine.RecognizeAsync(RecognizeMode.Multiple);
        } else {
            _recognitionEngine.RecognizeAsync(RecognizeMode.Single);
        }
    } else {                                                      //Toggle Speech Recognition off
        _startRecogButton.Text = "Start Speech Recognition";
        if (_friendlyStop) {
            _recognitionEngine.RecognizeAsyncStop(); //Stop after current phrase is finished.
        } else {
            _recognitionEngine.RecognizeAsyncCancel(); //Stop before current phrase is finished.
        }

    }
}

Thread Safety

All public static (Shared in Visual Basic) members of this type are thread-safe. Instance members are not guaranteed to be thread-safe.

Platforms

Development Platforms

Windows XP Professional with Service Pack 2 (SP2), Windows Server 2003, Windows Vista Ultimate Edition, Windows Vista Business Edition, Windows Vista Enterprise Edition

Target Platforms

See Also

Reference

SpeechRecognitionEngine Class
SpeechRecognitionEngine Members
Microsoft.Speech.Recognition Namespace