Windows 8 中的语音识别器中出现错误

我想将语音识别与我的应用程序集成。

我可以使用语音识别器

UI执行此操作，但是当我使用语音识别器创建自己的UI时，它会生成异常？为什么会这样..此代码始终生成异常并显示"引发异常"。

我不想使用SpeechRecognizerUI。

   private async void Button_Click(object sender, RoutedEventArgs e)
    {
        SpeechRecognizer speechrecognizer = new SpeechRecognizer();
        try
        {
            SpeechRecognitionResult result = await speechrecognizer.RecognizeAsync();
            if (result.TextConfidence != SpeechRecognitionConfidence.Rejected)
            {
                txt.Text = result.Text;
            }

        }
        catch (Exception err)
        {
            int privacyPolicyHResult = unchecked((int)0x80045509);
            if (err.HResult == privacyPolicyHResult)
            {
                MessageBox.Show("You will need to accept the speech privacy policy in order to use speech recognition in this app.");
            }
            else
            {
                MessageBox.Show("Exception Raised");
            }
        }