C#调用SAPI实现语音识别的两种方法

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");
            }
        }
    }
}