Silverlight中调用麦克风模拟录音机设备，存储为WAV音频

public  class WavAudioSink:AudioSink
{
     // 设置需要记录的内存流
     private MemoryStream _stream;
     // 设置当前的音频格式
     private AudioFormat _format;

     public Stream backingStream
    {
         get {  return _stream; }
    }

     public AudioFormat CurrentFormat
    {
         get {  return _format; }
    }

     protected  override  void OnCaptureStarted()
    {
        _stream =  new MemoryStream(1024);
    }

     protected  override  void OnCaptureStopped()
    {
    }

     protected  override  void OnFormatChange(AudioFormat audioFormat)
    {
         if (audioFormat.WaveFormat != WaveFormatType.Pcm)
             throw  new InvalidoperationException( "WavAudioSink只支持PCM音频格式");

        _format = audioFormat;
    }

     protected  override  void OnSamples( long sampleTime,  long sampleDuration,
         byte[] sampleData)
    {
         // 新的音频数据到达，将它们写入流
        _stream.Write(sampleData, 0, sampleData.Length);
    }
}

public  class SaveWAVHelper
  {
     public  static  void SavePcmToWav(Stream rawData, Stream output, AudioFormat audioFormat)
    {
         if (audioFormat.WaveFormat != WaveFormatType.Pcm)
             throw  new argumentexception( "Only PCM coding is supported.");

        BinaryWriter bwOutput =  new BinaryWriter(output);

         // -- rIFF 块
        bwOutput.Write( "RIFF".tocharArray());
         // 包的总长度
         // 计算的数据长度加上数据头的长度没有数据
         // 写数据(44 - 4 ("RIFF") - 4 (当前数据))
        bwOutput.Write(( uint)(rawData.Length + 36));
        bwOutput.Write( "WAVE".tocharArray());

         // -- FORMAT 块
        bwOutput.Write( "fmt ".tocharArray());
         // FORMAT 块的长度 (Binary, 总是 0x10)
        bwOutput.Write(( uint)0x10);
         // 总是 0x01
        bwOutput.Write(( ushort)0x01);
         // 通道数( 0x01=单声道, 0x02=立体声)
        bwOutput.Write(( ushort)audioFormat.ChAnnels);
         // 采样率 (Binary,  Hz为单位)
        bwOutput.Write(( uint)audioFormat.SamplesPerSecond);
         // 字节每秒
        bwOutput.Write(( uint)(audioFormat.bitsPerSample * audioFormat.SamplesPerSecond * 
            audioFormat.ChAnnels / 8));
         // 每个样品字节: 1=8 bit 单声道, 2=8 bit 立体声 or 16 bit 单声道, 4=16 bit 立体声
        bwOutput.Write(( ushort)(audioFormat.bitsPerSample * audioFormat.ChAnnels / 8));
         // 每个样品字节
        bwOutput.Write(( ushort)audioFormat.bitsPerSamplE);

         // -- DATA 块
        bwOutput.Write( "data".tocharArray());
         // DATA数据块的长度
        bwOutput.Write(( uint)rawData.Length);
         // 原始PCM数据如下
         // 复位rawData地位，记住它的原点位置
         // 恢复底。
         long originalRawDataStreamPosition = rawData.Position;
        rawData.Seek(0, SeekOrigin.begin);
         //追加到输出流中的所有数据从rawData流
         byte[] buffer =  new  byte[4096];
         int read;       
         // 循环读取字节数据
         while ((read = rawData.Read(buffer, 4096)) > 0)
        {
            bwOutput.Write(buffer, read);
        }
         //开始写入数据
        rawData.Seek(originalRawDataStreamPosition, SeekOrigin.begin);
  }
}

 < Grid x:Name= "LayoutRoot"  BACkground= "White">
        < Button Content= "开始录制"  Height= "28"  HorizontalAlignment= "Left"
                Margin= "30,15,0"  NAME= "btnRecord"  VerticalAlignment= "Top"
                Width= "71"  Click= "btnRecord_Click"  />
        < Button Content= "停止录制"  Height= "28"  HorizontalAlignment= "Left"
                Margin= "150,0"  NAME= "btnStopRecord"  VerticalAlignment= "Top"
                Width= "71"  Click= "btnStopRecord_Click"  />
        < Button Content= "保存音频"  Height= "28"  HorizontalAlignment= "Left"
                Margin= "268,0"  NAME= "btnSaveWav"  VerticalAlignment= "Top"
                Width= "71"  Click= "btnSaveWav_Click"  />
    < /Grid>

   public partial  class MainPage : UserControl
    {
     public MainPage()
    {
        InitializeComponent();

        btnRecord.IsEnabled =  true;
        btnStopRecord.IsEnabled =  false;
        btnSaveWav.IsEnabled =  false;
    }

     //声明私有变量
     private WavAudioSink _wavSink;
     private Capturesource _capturesource;
     private SaveFileDialog _saveFileDialog =  new SaveFileDialog() 
        { Filter =  "Audio files (*.wav)|*.wav" };

     private  void btnRecord_Click( object sender, routedEventArgs E)
    {

         //初始化_capturesource
        var audioDevice = CaptureDeviceConfiguration.GetDefaultAudioCaptureDevice();
        _capturesource =  new Capturesource() { AudioCaptureDevice = audioDevice };

         //有默认设置的设备且可以用来录制音频
         if (CaptureDeviceConfiguration.AllowedDeviceAccess ||
            CaptureDeviceConfiguration.requestDeviceAccess())
        {
             //判断当前没有开始录制音频
             if (_capturesource.State == CaptureState.Stopped)
            {
                 //初始化WavAudioSink
                _wavSink =  new WavAudioSink();
                _wavSink.Capturesource = _capturesource;
                 //开始录制音频
                _capturesource.Start();     

            }
        }


        btnRecord.IsEnabled =  false;
        btnStopRecord.IsEnabled =  true;
        btnSaveWav.IsEnabled =  false;
    }

     private  void btnStopRecord_Click( object sender, routedEventArgs E)
    {
         //如果当前状态为开始录制，则停止录制
         if (_capturesource.State == CaptureState.Started)
        {
            _capturesource.Stop();
        }


        btnRecord.IsEnabled =  false;
        btnStopRecord.IsEnabled =  false;
        btnSaveWav.IsEnabled =  true;
    }

     private  void btnSaveWav_Click( object sender, routedEventArgs E)
    {
         if (_saveFileDialog.ShowDialog() ==  false)
        {
             return;
        }
         //保存Wav文件
        Stream stream = _saveFileDialog.openFile();
        SaveWAVHelper.SavePcmToWav(_wavSink.backingStream, stream, _wavSink.CurrentFormat);

        stream.Close();

        messageBox.Show( "你的音频已经保存");


        btnRecord.IsEnabled =  true;
        btnStopRecord.IsEnabled =  false;
        btnSaveWav.IsEnabled =  false;
    }
}