我一直在网上寻找一种从C#控制计算机音频的方法。我找到了这段代码,它运行良好。
public static float GetMasterVolume()
{
// get the speakers (1st render + multimedia) device
IMMDeviceEnumerator deviceEnumerator = (IMMDeviceEnumerator)(new MMDeviceEnumerator());
IMMDevice speakers;
const int eRender = 0;
const int eMultimedia = 1;
deviceEnumerator.GetDefaultAudioEndpoint(eRender, eMultimedia, out speakers);
object o;
speakers.Activate(typeof(IAudioEndpointVolume).GUID, 0, IntPtr.Zero, out o);
IAudioEndpointVolume aepv = (IAudioEndpointVolume)o;
float volume = aepv.GetMasterVolumeLevelScalar();
Marshal.ReleaseComObject(aepv);
Marshal.ReleaseComObject(speakers);
Marshal.ReleaseComObject(deviceEnumerator);
return volume;
}
[ComImport]
[Guid("BCDE0395-E52F-467C-8E3D-C4579291692E")]
private class MMDeviceEnumerator
{
}
[Guid("5CDF2C82-841E-4546-9722-0CF74078229A"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
private interface IAudioEndpointVolume
{
void _VtblGap1_6();
float GetMasterVolumeLevelScalar();
}
[Guid("A95664D2-9614-4F35-A746-DE8DB63617E6"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
private interface IMMDeviceEnumerator
{
void _VtblGap1_1();
[PreserveSig]
int GetDefaultAudioEndpoint(int dataFlow, int role, out IMMDevice ppDevice);
}
[Guid("D666063F-1587-4E43-81F1-B948E807363F"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
private interface IMMDevice
{
[PreserveSig]
int Activate([MarshalAs(UnmanagedType.LPStruct)] Guid iid, int dwClsCtx, IntPtr pActivationParams, [MarshalAs(UnmanagedType.IUnknown)] out object ppInterface);
}
那就是 getVolume 函数。我认为一定有一种类似的方法来设置音量。我找到了这个方法:
HRESULT SetMasterVolumeLevelScalar(
[in] float fLevel,
[in] LPCGUID pguidEventContext
);
但我无法理解第二个参数。需要帮助,谢谢。