C#：引发事件时立即执行事件

Question

我目前正在使用 WPF 在 C# 中开发文本到语音应用程序。

要重新开始播放，我需要先取消，然后再开始。
我在 SpeakCompleted 事件处理程序中添加了一个函数 (speaker_finished())，在播放完成或取消时调用该函数。 speaker_finished() 调用 outputVisible(false) 将某些 UI 元素设置为不可见。但是当我重新开始播放时，我希望它们保持可见。
因为 outputVisible(true) 在 speaker.SpeakAsyncCancelAll() 之后被调用。这将取消播放，然后将 UI 元素设置为可见。问题是 speaker_finished() 在 buttonRestart_Click() 完成后被调用，因此为时已晚。我希望它在我用 speaker.SpeakAsyncCancelAll() 取消播放后和 outputVisible(true) 被调用之前立即被调用。

我怎样才能做到这一点？

SpeechSynthesizer speaker = new SpeechSynthesizer();

private void buttonRestart_Click(object sender, RoutedEventArgs e)
    {
        speaker.SpeakAsyncCancelAll();
        outputVisible(true);         //this function needs to be called after the function in the event handler
        speaker_Start();
    }

//function in the EventHandler of SpeakFinished
private void speaker_Finished(object sender, SpeakCompletedEventArgs e)
    {
        outputVisible(false);
    }

//function that changes the visibility
private void outputVisible(bool b)
    {
        if(b)
        {
            textBlockOutput.Visibility = Visibility.Visible;
            foreach (UIElement UIEle in GridPlaybackButtons.Children)
            {
                UIEle.Visibility = Visibility.Visible;
            }
        }
        else
        {
            textBlockOutput.Visibility = Visibility.Hidden;
            foreach (UIElement UIEle in GridPlaybackButtons.Children)
            {
                UIEle.Visibility = Visibility.Hidden;
            }
        }
    }

//function that starts the SpeechSynthesizer
private void speaker_Start()
    {
        if (speaker.State == SynthesizerState.Ready)
        {
            speaker.SpeakAsync(speakString);
        }
        else
        {
            MessageBox.Show("There already is a text being output!","Error!", MessageBoxButton.OK);
        }
    }

Answer 1

SpeechSynthesizer 也有一个 SpeakStarted 事件。像 SpeakCompleted

一样尝试为它添加一个事件处理程序

private void speaker_Started(object sender, SpeakStartedEventArgs e)
{
    outputVisible(true);
}

C#：引发事件时立即执行事件

C#: Execute Event immediately when it's raised

c#

wpf

events

text-to-speech