一、项目中一直用到了文字转语音的功能，需求也比较简单，就是将一段报警信息通过语音的方式播放出来，之前一直采用CS客户端，利用微软自带的Speech语音播放库就可以完成，
1.1 封装winSpedk类代码如下：
namespace Speak
{
using System;
using System.Runtime.CompilerServices;
using System.Speech.Synthesis;
using System.Threading;
using SpeechLib; public class WinSpeak
{
#region 属性
private SpeechSynthesizer Speak;
public event ErrorInfo ErrorInfoEvent;
private Thread thVoice;
private string strVoiceMsg;
SpVoice Voice = null;
private static WinSpeak _intence;
#endregion private WinSpeak()
{
Voice = new SpVoice();
} #region 方法
public static WinSpeak _Init()
{
if (_intence == null)
_intence = new WinSpeak(); return _intence;
}
/// <summary>
/// 读语音
/// </summary>
private void SpeakM()
{
try
{
if (Speak != null)
{
this.Speak.SpeakAsync(strVoiceMsg);
}
}
catch (Exception exception)
{
this.ErrInfo(exception);
}
}
/// <summary>
/// 异步播放文本语音
/// </summary>
/// <param name="msg"></param>
public void BeginSpeakText(string msg)
{
try
{
if (Speak != null)
{
Speak.SpeakAsyncCancelAll();
Speak.Dispose();
} if (thVoice != null && thVoice.ThreadState == ThreadState.Running)
{
thVoice.Abort();
} Speak = new SpeechSynthesizer();
Speak.SetOutputToDefaultAudioDevice(); strVoiceMsg = msg; //thVoice = new Thread(new ThreadStart(SpeakM));
//thVoice.Start();
Speak.SpeakAsync(msg); GC.Collect();
GC.WaitForPendingFinalizers();
}
catch (Exception exception)
{
this.ErrInfo(exception);
}
}
/// <summary>
/// 播放文本语音
/// </summary>
/// <param name="msg"></param>
public void SpeakText(string msg)
{
try
{
this.Speak = new SpeechSynthesizer();
this.Speak.Speak(msg);
this.Speak.SetOutputToNull();
this.Speak.Dispose();
}
catch (Exception exception)
{
this.ErrInfo(exception);
}
}
/// <summary>
/// Speech播放文本合成语音
/// </summary>
/// <param name="msg"></param>
public void Speech_SpeakText(string msg)
{
try
{
if (Voice != null)
{
Voice.Speak(null, SpeechVoiceSpeakFlags.SVSFPurgeBeforeSpeak);
Voice.Speak(msg, SpeechVoiceSpeakFlags.SVSFlagsAsync);
}
}
catch (Exception ex)
{
this.ErrInfo(ex);
}
}
/// <summary>
/// 关闭语音释放资源
/// </summary>
public void SpeakClose()
{
try
{
if (Speak != null)
{
this.Speak.SpeakAsyncCancelAll();
this.Speak.Dispose();
} if (Voice != null)
{
Voice.Speak(null, SpeechVoiceSpeakFlags.SVSFPurgeBeforeSpeak);
}
}
catch (Exception ex)
{
cGlobe_Log.Error(cGlobe_Log.GetMethodInfo() + ex.Message);
}
}
/// <summary>
/// 获取错误信息
/// </summary>
/// <param name="str"></param>
private void ErrInfo(Exception str)
{
if (this.ErrorInfoEvent != null)
{
this.ErrorInfoEvent(str);
}
}
#endregion ~WinSpeak()
{
try
{
if (Speak != null)
{
this.Speak.SpeakAsyncCancelAll();
this.Speak.Dispose();
}
}
catch (Exception exception)
{
//this.ErrInfo(exception);
}
}
}
}
1.2 调用如下（一个同步播放、一个异步播放）：
private void btnTest_Click(object sender, EventArgs e)
{
try
{
string strSep = txtWord.Text;
SFBR.WinSpeak._Init().Speech_SpeakText(strSep);
}
catch (Exception ex)
{ }
} private void button1_Click(object sender, EventArgs e)
{
try
{
string strSep = txtWord.Text;
SFBR.WinSpeak._Init().BeginSpeakText(strSep);
}
catch (Exception ex)
{ }
}
二、 最近客户提出需求需要在BS系统实现文字语音播放的功能，因不能接入外网不能调用第三方服务等，最后想到了一个解决方案:先把文字转化为音频文件，再把音频文件以流的形式推送到BS端进行播放；
2.1 同样可以利用微软自带的Speech语音播放库将一段文本转化为音频文件：
2.2 封装 SpeechService文字转换音频文件类
public class SpeechService
{
private static SpeechSynthesizer synth = null;
/// <summary>
/// 返回一个SpeechSynthesizer对象
/// </summary>
/// <returns></returns>
private static SpeechSynthesizer GetSpeechSynthesizerInstance()
{
if (synth == null)
{
synth = new SpeechSynthesizer();
}
return synth;
}
/// <summary>
/// 保存语音文件
/// </summary>
/// <param name="text"></param>
public static void SaveMp3(string strFileName,string spText)
{
synth = GetSpeechSynthesizerInstance();
synth.Rate = ;
synth.Volume = ;
synth.SetOutputToWaveFile(strFileName);
synth.Speak(spText);
synth.SetOutputToNull();
}
}
2.3 接下来就是将音频文件以文件流的形式推送到前端播放：
public async Task<ActionResult> PlayWav(string id,string spText)
{
string strPath = Server.MapPath("~\\MP4\\" + id + ".wav");
SpeechService.SaveMp3(strPath, spText);
try
{
using (FileStream fileStream = new FileStream(strPath, FileMode.Open))
{
byte[] fileByte = new byte[fileStream.Length];
fileStream.Seek(, SeekOrigin.Begin);
fileStream.Read(fileByte, , (int)fileStream.Length);
long fSize = fileStream.Length;
long startbyte = ;
long endbyte = fSize - ;
int statusCode = ;
if ((Request.Headers["Range"] != null))
{
//Get the actual byte range from the range header string, and set the starting byte.
string[] range = Request.Headers["Range"].Split(new char[] { '=', '-' });
startbyte = Convert.ToInt64(range[]);
if (range.Length > && range[] != "") endbyte = Convert.ToInt64(range[]);
//If the start byte is not equal to zero, that means the user is requesting partial content.
if (startbyte != || endbyte != fSize - || range.Length > && range[] == "")
{ statusCode = ; }//Set the status code of the response to 206 (Partial Content) and add a content range header.
}
long desSize = endbyte - startbyte + ;
//Headers
Response.StatusCode = statusCode;
Response.ContentType = "audio/mpeg";
Response.AddHeader("Content-Accept", Response.ContentType);
Response.AddHeader("Content-Length", desSize.ToString());
Response.AddHeader("Content-Range", string.Format("bytes {0}-{1}/{2}", startbyte, endbyte, fSize));
return File(fileByte, Response.ContentType); }
}
catch (Exception ex)
{
throw;
}
}
注意：返回的必须为异步（ async Task）不然会报错，因为文字音频转换涉及到异步调用
2.4 前端展示
2.5 运行截图如下：
BS实现文字音频调用demo地址如下：
https://github.com/lxshwyan/SpeechBSDemo.git