如何在C＃中将异步方法与同步方法结合起来？

Question

我从main方法调用：

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

我真正想要做的是Wait直到“欢迎来到尼泊尔”正在在mytextblck发言，然后写“你好”。

我已经去了几个线程和工作，但没有什么可以使它的工作。

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

这听起来像你真正想要的是当MediaEnded触发事件触发的文本改变。

您可以做你ChangeToSpeech方法中，虽然这将是一个难看一点：

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; 
    } 
}