C# 设置软件扬声器音量大小

public static class VolumeHelper
{[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);public static double CurrentVolume = 50;public static void SetVolume(double volumeSize){if (volumeSize < 0)volumeSize = 0;if (volumeSize > 100)volumeSize = 100;System.UInt32 Value = (System.UInt32)((double)0xffff * (double)volumeSize / 100.0);//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CurrentVolume = volumeSize;}public static int GetVolume(){System.UInt32 value = 0;waveOutGetVolume(0, out value);return (int)(value >> 16);}
}

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