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));
            }
        }
    }

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();