C#中调用SAPI实现语音识别的2种方法

通过微软的sapi，不仅仅可以实现语音合成tts，同样可以实现语音识别sr。下面我们就介绍并贴出相关代码。主要有两种方式：

1、使用com组件技术，不管是c++，c#，delphi都能玩的转，开发出来的东西在xp和win7都能跑。（注意要引入系统组件speechlib，xp要安装识别引擎）
2、使用win7的windows api，其实最终还是调用了sapi，所以开发出来的东西就只能在win7上面跑。

其实不管是哪一种，都是调用sapi，可能后一种代码比较简单。

使用第一种方式，需要注意在com选项卡里面的microsoft speech  object  library引用

public class sprecognition
  {
    private static sprecognition _instance = null;
    private speechlib.ispeechrecogrammar isrg;
    private speechlib.spsharedrecocontextclass ssrcontex = null;

    public delegate void stringevent(string str);
    public stringevent setmessage;

    private sprecognition()
    {
      ssrcontex = new spsharedrecocontextclass();
      isrg = ssrcontex.creategrammar(1);
      speechlib._ispeechrecocontextevents_recognitioneventhandler rechandle =
         new _ispeechrecocontextevents_recognitioneventhandler(contexrecognition);
      ssrcontex.recognition += rechandle;
    }
    public void beginrec()
    {
      isrg.dictationsetstate(speechrulestate.sgdsactive);
    }
    public static sprecognition instance()
    {
      if (_instance == null)
        _instance = new sprecognition();
      return _instance;
    }
    public void closerec()
    {
      isrg.dictationsetstate(speechrulestate.sgdsinactive);
    }
    private void contexrecognition(int iindex, object obj, speechlib.speechrecognitiontype type, speechlib.ispeechrecoresult result)
    {
      if (setmessage != null)
      {
        setmessage(result.phraseinfo.gettext(0, -1, true));
      }
    }
  }

第二种同样需要引入，不过引入的是win7中的.net3.5类库

using system;
using system.collections.generic;
using system.linq;
using system.text;
using system.speech;
using system.speech.recognition;
using system.globalization;
using system.windows.forms;

namespace studybeta
{
  public class srecognition
  {
    public speechrecognitionengine recognizer = null;//语音识别引擎
    public dictationgrammar dictationgrammar = null; //自然语法
    public system.windows.forms.control cdisplay; //显示控件

    public srecognition(string[] fg) //创建关键词语列表
    {
      cultureinfo myciintl = new cultureinfo("en-us");
      foreach (recognizerinfo config in speechrecognitionengine. installedrecognizers())//获取所有语音引擎
      {
    if (config.culture.equals(myciintl) && config.id == "ms-1033-80-desk" )
        {
          recognizer = new speechrecognitionengine(config);
          break;
        }//选择美国英语的识别引擎
      }
      if (recognizer != null)
      {
        initializespeechrecognitionengine(fg);//初始化语音识别引擎
        dictationgrammar = new dictationgrammar();
      }
      else
      {
        messagebox.show("创建语音识别失败");
      }
    }
    private void initializespeechrecognitionengine(string[] fg)
    {
      recognizer.setinputtodefaultaudiodevice();//选择默认的音频输入设备
      grammar customgrammar = createcustomgrammar(fg);
  //根据关键字数组建立语法
      recognizer.unloadallgrammars();
      recognizer.loadgrammar(customgrammar);
  //加载语法
recognizer.speechrecognized += new eventhandler <speechrecognizedeventargs>(recognizer_speechrecognized);
recognizer.speechhypothesized += new eventhandler <speechhypothesizedeventargs>(recognizer_speechhypothesized);
    }
    public void beginrec(control tbresult)//关联窗口控件
    {
      turnspeechrecognitionon();
      turndictationon();
      cdisplay = tbresult;
    }
    public void over()//停止语音识别引擎
    {
      turnspeechrecognitionoff();
    }
    public virtual grammar createcustomgrammar(string[] fg) //创造自定义语法
    {
      grammarbuilder grammarbuilder = new grammarbuilder();
      grammarbuilder.append(new choices(fg));
      return new grammar(grammarbuilder);
    }
    private void turnspeechrecognitionon()//启动语音识别函数
    {
      if (recognizer != null)
      {
        recognizer.recognizeasync(recognizemode.multiple); 
//识别模式为连续识别
      }
      else
      {
        messagebox.show("创建语音识别失败");
      }
    }
    private void turnspeechrecognitionoff()//关闭语音识别函数
    {
      if (recognizer != null)
      {
        recognizer.recognizeasyncstop();
        turndictationoff();
      }
      else
      {
        messagebox.show("创建语音识别失败");
      }
    }
private void recognizer_speechrecognized(object sender, speechrecognized eventargs e)
    {
  //识别出结果完成的动作，通常把识别结果传给某一个控件
      string text = e.result.text;
      cdisplay.text = text;
    }
    private void turndictationon()
    {
      if (recognizer != null)
      {
        recognizer.loadgrammar(dictationgrammar);
  //加载自然语法
      }
      else
      {
        messagebox.show("创建语音识别失败");
      }
    }
    private void turndictationoff()
    {
      if (dictationgrammar != null)
      {
        recognizer.unloadgrammar(dictationgrammar);
  //卸载自然语法
      }
      else
      {
        messagebox.show("创建语音识别失败");
      }
    }
  }
}