SpeechRecognitionEngine.RecognizeCompleted Event

RecognizeCompleted events are generated on completion of an asynchronous recognition operation (initiated by calls to RecognizeAsync).

An instance of RecognizeCompletedEventArgs is passed to the RecognizeCompleted handler, which can use the instance to obtain an RecognitionResult instance [(P:System.Speech.Recognition.RecognizeCompletedEventArgs.Result]), which will be null if recognition failed due either to time out or grammar failure.

To obtain details on the best rejected recognition candidates, an application must have a handler for SpeechRecognitionRejected.

If a timeout occurred, or audio input ended can be determined from the InitialSilenceTimeout, BabbleTimeout, or InputStreamEnded properties on the instance of RecognizeCompletedEventArgs passed to the handler.

The example below show a simple anonymous method used as the handler for RecognizeCompleted. The handler stores the result of the recognition operation, if Result is not null and updates a state variable. If an error condition exists, a message is sent to the end user.

_recognizer.RecognizeCompleted += delegate(object sender, RecognizeCompletedEventArgs completedEventArgs) {
    _recognitionDone = true;
    if (completedEventArgs.Result != null) {
        _completedEventArgs = completedEventArgs;
        _recognitionSuccess = true;
    } else {
        _completedEventArgs = null;
        _recognitionSuccess = false;
        MessageBox.Show(String.Format("Recognition failed\n",
                                      "InitialSilenceTimeout: {0}\n",
                                      "BabbleTimeout: {0}\n",
                                      "InputStreamEnded: {2}\n",
                                      completedEventArgs.InitialSilenceTimeout,
                                      completedEventArgs.BabbleTimeout,
                                      completedEventArgs.InputStreamEnded));
    }
};

• Full trust for the immediate caller. This member cannot be used by partially trusted code. For more information, see Using Libraries from Partially Trusted Code.

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

.NET Framework

Reference