如何在 ASP.NET MVC 中使用 Windows 语音合成器

我尝试使用System.Speech在 ASP.NET mvc 应用程序中生成语音的类。

[HttpPost]
public  ActionResult TTS(string text)
{
   SpeechSynthesizer speechSynthesizer = new SpeechSynthesizer();
   speechSynthesizer.Speak(text);
   return View();
}

但它给出了以下错误。

 System.InvalidOperationException: 'An asynchronous operation cannot be 
 Started at this time. Asynchronous operations may only be started within an 
 asynchronous handler or module or during certain events in the Page lifecycle. 
 If this exception occurred while executing a Page, ensure that the Page is
 marked <%@ Page Async="true" %>. 
 This exception may also indicate an attempt to call an "async void" method, 
 which is generally unsupported within ASP.NET request processing. Instead, 
the asynchronous method should return a Task, and the caller should await it.

我在 wpf 应用程序中使用了 System.Speech 类和异步方法。

1. System.Speech 类可以在 ASP.NET mvc 应用程序中使用吗？

2. 怎么做？

3. 应该在哪里<%@ Page Async="true" %>是 放置？

答案是：yes， 您可以使用System.SpeechMVC 中的类。

我想你可以尝试使用async控制器动作方法及使用SpeechSynthesizer.Speak https://msdn.microsoft.com/en-us/library/system.speech.synthesis.speechsynthesizer.speak(v=vs.110).aspx with Task.Run像这样的方法：

[HttpPost]
public async Task<ActionResult> TTS(string text)
{
    Task<ViewResult> task = Task.Run(() =>
    {
        using (SpeechSynthesizer speechSynthesizer = new SpeechSynthesizer())
        {
            speechSynthesizer.Speak(text);
            return View();
        }
    });
    return await task;
}

但是，如上面的示例所示，生成的声音在服务器上播放，因为上面的代码在服务器端而不是客户端运行。要启用在客户端播放，您可以使用SetOutputToWaveFile https://msdn.microsoft.com/en-us/library/ms586883(v=vs.110).aspx方法及用途audio返回视图页面时播放音频内容的标签，如下例所示（假设您在 CSHTML 视图中使用 HTML 5）：

控制器

[HttpPost]
public async Task<ActionResult> TTS(string text)
{
    // you can set output file name as method argument or generated from text
    string fileName = "fileName";
    Task<ViewResult> task = Task.Run(() =>
    {
        using (SpeechSynthesizer speechSynthesizer = new SpeechSynthesizer())
        {
            speechSynthesizer.SetOutputToWaveFile(Server.MapPath("~/path/to/file/") + fileName + ".wav");
            speechSynthesizer.Speak(text);

            ViewBag.FileName = fileName + ".wav";
            return View();
        }
    });
    return await task;
}

View

<audio autoplay="autoplay" src="@Url.Content("~/path/to/file/" + ViewBag.FileName)">
</audio>

或者您可以将操作类型更改为FileContentResult并使用MemoryStream with SetOutputToWaveStream https://msdn.microsoft.com/en-us/library/system.speech.synthesis.speechsynthesizer.setoutputtowavestream(v=vs.110).aspx让用户自己播放音频文件：

Task<FileContentResult> task = Task.Run(() =>
{
    using (SpeechSynthesizer speechSynthesizer = new SpeechSynthesizer())
    {
        using (MemoryStream stream = new MemoryStream())
        {
            speechSynthesizer.SetOutputToWaveStream(stream);
            speechSynthesizer.Speak(text);
            var bytes = stream.GetBuffer();
            return File(bytes, "audio/x-wav");
        }
    }
});

参考：

在 ASP.NET MVC 中使用异步方法 https://learn.microsoft.com/en-us/aspnet/mvc/overview/performance/using-asynchronous-methods-in-aspnet-mvc-4

类似问题：

mvc中如何使用语音 https://forums.asp.net/t/2003629.aspx?How%20to%20use%20speech%20in%20mvc

System.Speech.Synthesis 在 2012 R2 上因 CPU 高而挂起 https://stackoverflow.com/questions/32236923/system-speech-synthesis-hangs-with-high-cpu-on-2012-r2