如何在C＃中將異步方法與同步方法結合起來？

Question

我是從主要方法調用的：

public MainPage()
{
  Text_to_Speech.changetospeech("Welcome to Nepal!", newmedia).Wait();
  mytxtblck.Text="Hello from Nepal!"
}

我真正想做的是Wait “歡迎來到尼泊爾”，然后在mytextblck寫下“Hello”。

我已經去了幾個線程並且工作了，但沒有任何東西可以使它工作。

public async static Task changetospeech(string text, MediaElement mediaa)
{
   var synth = new SpeechSynthesizer();
   var voices = SpeechSynthesizer.AllVoices;

   synth.Voice = voices.First(x => x.Gender == VoiceGender.Female );
   SpeechSynthesisStream stream = await synth.SynthesizeTextToStreamAsync(text);

   MediaElement media = mediaa;
   media.SetSource(stream,stream.ContentType);
   media.Play();   
}

Answer 1

聽起來你真正想要的是在觸發MediaEnded事件時觸發文本更改。

你可以在你的ChangeToSpeech方法中做到這一點，雖然它會有點難看：

public async static Task ChangeToSpeech(string text, MediaElement media)
{
    var synth = new SpeechSynthesizer();
    var voices = SpeechSynthesizer.AllVoices;

    synth.Voice = voices.First(x => x.Gender == VoiceGender.Female);

    SpeechSynthesisStream stream = await synth.SynthesizeTextToStreamAsync(text);

    var tcs = new TaskCompletionSource<int>();
    RoutedEventHandler handler = delegate { tcs.TrySetResult(10); };
    media.MediaEnded += handler;
    try
    {
        media.SetSource(stream, stream.ContentType);
        media.Play();
        // Asynchronously wait for the event to fire
        await tcs.Task;
    }
    finally
    {
        media.MediaEnded -= handler;
    }
}