C# 二种方法控制系统音量/麦克风大小

场景:在做播放设备的时候需要控制音量的大小，下面几种方法将满足你的要求

方法一: 改变系统音量设置

 

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[DllImport( "user32.dll" )] static extern void keybd_event( byte bVk, byte bScan, UInt32 dwFlags, UInt32 dwExtraInfo);   [DllImport( "user32.dll" )] static extern Byte MapVirtualKey(UInt32 uCode, UInt32 uMapType);   private const byte VK_VOLUME_MUTE = 0xAD ; private const byte VK_VOLUME_DOWN = 0xAE ; private const byte VK_VOLUME_UP = 0xAF ; private const UInt32 KEYEVENTF_EXTENDEDKEY = 0x0001 ; private const UInt32 KEYEVENTF_KEYUP = 0x0002 ;   /// <summary> /// 改变系统音量大小，增加 /// </summary> public void VolumeUp() {      keybd_event(VK_VOLUME_UP, MapVirtualKey(VK_VOLUME_UP, 0 ), KEYEVENTF_EXTENDEDKEY, 0 );      keybd_event(VK_VOLUME_UP, MapVirtualKey(VK_VOLUME_UP, 0 ), KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP, 0 ); }   /// <summary> /// 改变系统音量大小，减小 /// </summary> public void VolumeDown() {      keybd_event(VK_VOLUME_DOWN, MapVirtualKey(VK_VOLUME_DOWN, 0 ), KEYEVENTF_EXTENDEDKEY, 0 );      keybd_event(VK_VOLUME_DOWN, MapVirtualKey(VK_VOLUME_DOWN, 0 ), KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP, 0 ); }   /// <summary> /// 改变系统音量大小，静音 /// </summary> public void Mute() {      keybd_event(VK_VOLUME_MUTE, MapVirtualKey(VK_VOLUME_MUTE, 0 ), KEYEVENTF_EXTENDEDKEY, 0 );      keybd_event(VK_VOLUME_MUTE, MapVirtualKey(VK_VOLUME_MUTE, 0 ), KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP, 0 ); }

方法二: 改变程序音量，但不改变系统音量设置

 

 

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[DllImport( "Winmm.dll" )] private static extern int waveOutSetVolume( int hwo, System.UInt32 pdwVolume);   [DllImport( "Winmm.dll" )] private static extern uint waveOutGetVolume( int hwo, out    System.UInt32 pdwVolume);  #region   private int volumeMinScope = 0 ; private int volumeMaxScope = 100 ; private int volumeSize = 100 ;   /// <summary> /// 音量控制，但不改变系统音量设置 /// </summary> public int VolumeSize {      get { return volumeSize; }      set { volumeSize = value; } }   public void SetCurrentVolume() {      if (volumeSize < 0 )      {          volumeSize = 0 ;      }        if (volumeSize > 100 )      {          volumeSize = 100 ;      }      System.UInt32 Value = (System.UInt32)(( double ) 0xffff * ( double )volumeSize / ( double )(volumeMaxScope - v                            olumeMinScope)); //先把trackbar的value值映射到0x0000～0xFFFF范围          //限制value的取值范围      if (Value < 0 )      {          Value = 0 ;      }        if (Value > 0xffff )      {          Value = 0xffff ;      }        System.UInt32 left = (System.UInt32)Value; //左声道音量      System.UInt32 right = (System.UInt32)Value; //右      waveOutSetVolume( 0 , left << 16 | right); //"<<"左移，“|”逻辑或运算 }