c# - 如何停止/切断 iOS 上的 xamarin essentials 文本到语音以开始新的语音

Question

无法停止 xamarin essentials 文本到语音以启动新的文本到语音“SpeakAsync”调用 w/Xamarin.Forms。

将此应用程序用作“练习电话”的模拟接线员，我想在用户挂断电话时切断接线员说“你好，这是......”，并使用 speak async 开始切断之前的文字转语音后立即说“此通话已结束”

await TextToSpeech.SpeakAsync("Hello this is the operator, thank you for calling, how can I help you?"
    , SpeechTokenSource.Token);

这目前在 android 上按预期工作

public void CancelSpeech()
{
    if (SpeechTokenSource?.IsCancellationRequested ?? true)
    return;

    SpeechTokenSource.Cancel();
}

尝试使用文档中列出的取消 token (https://learn.microsoft.com/en-us/xamarin/essentials/text-to-speech)但是，我无法让当前的“SpeakAsync”语音立即停止在 iOS 上播放，也无法让下一个 speakasync 命令在初始文本转语音被取消后开始在 iOS 上说出文本。

   CancelSpeech();

   IsCallActive = false;
   DialedText = null;

   //Reset speech cancellation token
   SpeechTokenSource = new CancellationTokenSource();

   await TextToSpeech.SpeakAsync("This call has ended. Goodbye."
   , SpeechTokenSource.Token);

错误记录在 iOS 输出中:“[AXTTSCommon] _BeginSpeaking:无法开始播放”

有什么我想念的吗？如何取消当前正在播放的文字转语音并立即开始下一个语音？

编辑:

这需要通过单击按钮来完成(同时取消当前语音和开始“此通话已结束”语音)

Answer 1

我无法重现您的问题。

以下代码使用 Xamarin.Essentials v1.3.0 适用于 iOS 和 Android。和 Xamarin.Forms v4.2.0.709249 .

当点击 speakButton 时，将朗读文本；当正在朗读文本时点击 cancelButton，将停止朗读。

在 iOS 和 Android 上取消 SpeakAsync 时有一个区别:

• 在 iOS 上，当前正在说的单词说完，然后停止说话
• 在 Android 上，当前正在说的词被切断并且停止说话

示例代码

可在此处找到完整的示例应用程序:https://github.com/brminnick/CancelTextToSpeechSample/tree/master

using System;
using System.Threading;
using Xamarin.Forms;

namespace CancelTextToSpeechSample
{
    public class App : Application
    {
        public App()
        {
            MainPage = new CancelSpeakPage();
        }

        class CancelSpeakPage : ContentPage
        {
            const string _spokenText = "Oh, supercalifragilisticexpialidocious! Even though the sound of it, Is something quite atrocious, If you say it loud enough, You'll always sound precocious, Supercalifragilisticexpialidocious!";

            CancellationTokenSource _speakButtonCancellationTokenSource;

            public CancelSpeakPage()
            {
                var speakButton = new Button { Text = "Sing" };
                speakButton.Clicked += HandleSpeakButtonClicked;

                var cancelButton = new Button { Text = "Cancel Song" };
                cancelButton.Clicked += HandleCancelButtonClicked;

                Content = new StackLayout
                {
                    VerticalOptions = LayoutOptions.Center,
                    HorizontalOptions = LayoutOptions.Center,

                    Children =
                    {
                        speakButton,
                        cancelButton
                    }
                };
            }

            void HandleCancelButtonClicked(object sender, EventArgs e)
            {
                _speakButtonCancellationTokenSource?.Cancel();
            }

            async void HandleSpeakButtonClicked(object sender, EventArgs e)
            {
                if (_speakButtonCancellationTokenSource?.IsCancellationRequested is false)
                    _speakButtonCancellationTokenSource.Cancel();

                _speakButtonCancellationTokenSource = new CancellationTokenSource();
                await Xamarin.Essentials.TextToSpeech.SpeakAsync(_spokenText, _speakButtonCancellationTokenSource.Token);
            }
        }
    }
}