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} |
