我正在嘗試IAudioEndpointVolume::SetMute使用 Interop 從 C#調用 Windows Core Audio 。使用 C++ 實現，它工作正常。但是當我嘗試從 C# 應用程序執行相同的調用時，沒有任何變化。C# 應用程序的奇怪之處在于，如果我調用SetMute什么都不會發生，但是如果我調用SetMasterVolumeLevelScalar，它會有效地改變音量。我的實現是這樣的：using System;using System.Runtime.InteropServices;namespace App{ [ComImport] [Guid("A95664D2-9614-4F35-A746-DE8DB63617E6"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)] interface IMMDeviceEnumerator { void _VtblGap1_1(); int GetDefaultAudioEndpoint(int dataFlow, int role, out IMMDevice ppDevice); } [Guid("D666063F-1587-4E43-81F1-B948E807363F"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)] interface IMMDevice { int Activate([MarshalAs(UnmanagedType.LPStruct)] Guid iid, int dwClsCtx, IntPtr pActivationParams, [MarshalAs(UnmanagedType.IUnknown)] out object ppInterface); int OpenPropertyStore([MarshalAs(UnmanagedType.U4)] UInt32 accessMode, [MarshalAs(UnmanagedType.Interface)] out object properties); int GetId([MarshalAs(UnmanagedType.LPWStr)] out string strId); }Interop 實現有什么問題嗎？
1 回答
慕村9548890
TA貢獻1884條經驗 獲得超4個贊
我努力嘗試并最終成功，這些“_VtblGaps_”是關鍵......只需將所有內容復制粘貼到一個新的 C# 腳本中并從您的程序腳本中使用：
using System;
using System.Runtime.InteropServices;
using System.Windows.Forms;
namespace MMDeviceAPI
{
public class MMDeviceController
{
[ComImport]
[Guid("BCDE0395-E52F-467C-8E3D-C4579291692E")]
private class MMDeviceEnumerator
{
}
[Guid("A95664D2-9614-4F35-A746-DE8DB63617E6"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
private interface IMMDeviceEnumerator
{
void _VtblGap1_1();
//void _VtblGap1_5(); /// (Alternative)
[PreserveSig]
int GetDefaultAudioEndpoint(EDataFlow dataFlow, ERole 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);
void _VtblGap1_1();
int GetId([MarshalAs(UnmanagedType.LPWStr)] out string strId);
}
[Guid("5CDF2C82-841E-4546-9722-0CF74078229A"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
private interface IAudioEndpointVolume
{
}
[Guid("5CDF2C82-841E-4546-9722-0CF74078229A"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
private interface IGetChannelCount : IAudioEndpointVolume
{
void _VtblGap1_2();
int GetChannelCount(ref uint pnChannelCount);
}
[Guid("5CDF2C82-841E-4546-9722-0CF74078229A"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
private interface IGetChannelVolumeLevelScalar : IAudioEndpointVolume
{
void _VtblGap1_10();
int GetChannelVolumeLevelScalar(uint nChannel, ref float pfLevel);
}
[Guid("5CDF2C82-841E-4546-9722-0CF74078229A"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
private interface IGetMasterVolumeLevelScalar : IAudioEndpointVolume
{
void _VtblGap1_6();
int GetMasterVolumeLevelScalar(ref float pfLevel);
}
[Guid("5CDF2C82-841E-4546-9722-0CF74078229A"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
private interface IGetMute : IAudioEndpointVolume
{
void _VtblGap1_12();
int GetMute([MarshalAs(UnmanagedType.Bool)] ref bool pbMute);
}
[Guid("5CDF2C82-841E-4546-9722-0CF74078229A"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
private interface ISetChannelVolumeLevelScalar : IAudioEndpointVolume
{
void _VtblGap1_8();
int SetChannelVolumeLevelScalar(uint nChannel, float fLevel, [MarshalAs(UnmanagedType.LPStruct)] Guid pguidEventContext);
}
[Guid("5CDF2C82-841E-4546-9722-0CF74078229A"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
private interface ISetMasterVolumeLevelScalar : IAudioEndpointVolume
{
void _VtblGap1_4();
int SetMasterVolumeLevelScalar(float fLevel, [MarshalAs(UnmanagedType.LPStruct)] Guid pguidEventContext);
}
[Guid("5CDF2C82-841E-4546-9722-0CF74078229A"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
private interface ISetMute : IAudioEndpointVolume
{
void _VtblGap1_11();
int SetMute([MarshalAs(UnmanagedType.Bool)] bool bMute, [MarshalAs(UnmanagedType.LPStruct)] Guid pguidEventContext);
}
public enum EDataFlow { eRender, eCapture, eAll };
public enum ERole { eConsole, eMultimedia, eCommunications };
///====================================================================================================
private static IAudioEndpointVolume GetMMDeviceAudioEndpointVolume(EDataFlow dataFlow, ERole role)
{
IMMDeviceEnumerator MMDeviceEnumerator = (IMMDeviceEnumerator)(new MMDeviceEnumerator());
MMDeviceEnumerator.GetDefaultAudioEndpoint(dataFlow, role, out IMMDevice MMDevice);
MMDevice.Activate(typeof(IAudioEndpointVolume).GUID, 0, IntPtr.Zero, out object o);
IAudioEndpointVolume AudioEndpointVolume = (IAudioEndpointVolume)o;
Marshal.ReleaseComObject(MMDevice);
Marshal.ReleaseComObject(MMDeviceEnumerator);
return AudioEndpointVolume;
}
public static uint GetChannelCount(EDataFlow dataFlow, ERole role)
{
IGetChannelCount AudioEndpointVolume = (IGetChannelCount)GetMMDeviceAudioEndpointVolume(dataFlow, role);
uint returnValue = 0;
AudioEndpointVolume.GetChannelCount(ref returnValue);
Marshal.ReleaseComObject(AudioEndpointVolume);
return returnValue;
}
public static float GetChannelVolumeLevelScalar(EDataFlow dataFlow, ERole role, uint channel)
{
IGetChannelVolumeLevelScalar AudioEndpointVolume = (IGetChannelVolumeLevelScalar)GetMMDeviceAudioEndpointVolume(dataFlow, role);
float returnValue = 0;
AudioEndpointVolume.GetChannelVolumeLevelScalar(channel, ref returnValue);
Marshal.ReleaseComObject(AudioEndpointVolume);
return returnValue;
}
public static float GetMasterVolumeLevelScalar(EDataFlow dataFlow, ERole role)
{
IGetMasterVolumeLevelScalar AudioEndpointVolume = (IGetMasterVolumeLevelScalar)GetMMDeviceAudioEndpointVolume(dataFlow, role);
float returnValue = 0f;
AudioEndpointVolume.GetMasterVolumeLevelScalar(ref returnValue);
Marshal.ReleaseComObject(AudioEndpointVolume);
return returnValue;
}
public static bool GetMute(EDataFlow dataFlow, ERole role)
{
IGetMute AudioEndpointVolume = (IGetMute)GetMMDeviceAudioEndpointVolume(dataFlow, role);
bool returnValue = false;
AudioEndpointVolume.GetMute(ref returnValue);
Marshal.ReleaseComObject(AudioEndpointVolume);
return returnValue;
}
public static void SetChannelVolumeLevelScalar(EDataFlow dataFlow, ERole role, uint channel, float volume)
{
ISetChannelVolumeLevelScalar AudioEndpointVolume = (ISetChannelVolumeLevelScalar)GetMMDeviceAudioEndpointVolume(dataFlow, role);
AudioEndpointVolume.SetChannelVolumeLevelScalar(channel, volume, Guid.Empty);
Marshal.ReleaseComObject(AudioEndpointVolume);
}
public static void SetMasterVolumeLevelScalar(EDataFlow dataFlow, ERole role, float volume)
{
ISetMasterVolumeLevelScalar AudioEndpointVolume = (ISetMasterVolumeLevelScalar)GetMMDeviceAudioEndpointVolume(dataFlow, role);
AudioEndpointVolume.SetMasterVolumeLevelScalar(volume, Guid.Empty);
Marshal.ReleaseComObject(AudioEndpointVolume);
}
public static void SetMute(EDataFlow dataFlow, ERole role, bool mute)
{
ISetMute AudioEndpointVolume = (ISetMute)GetMMDeviceAudioEndpointVolume(dataFlow, role);
AudioEndpointVolume.SetMute(mute, Guid.Empty);
Marshal.ReleaseComObject(AudioEndpointVolume);
}
///====================================================================================================
public static void TestFunctionality()
{
int device = 0;
EDataFlow dataFlow;
ERole eRole;
while (true)
{
device++;
switch (device)
{
case 1:
dataFlow = EDataFlow.eRender;
eRole = ERole.eMultimedia;
break;
case 2:
dataFlow = EDataFlow.eCapture;
eRole = ERole.eMultimedia;
break;
default:
return;
}
MessageBox.Show($"[EDataFlow & ERole]: {dataFlow.ToString()}_{eRole.ToString()}");
uint channels = GetChannelCount(dataFlow, eRole); MessageBox.Show("[GetChannelCount]: " + channels);
MessageBox.Show("[GetChannelVolumeLevelScalar #0]: " + GetChannelVolumeLevelScalar(dataFlow, eRole, 0).ToString());
if (channels > 1) { MessageBox.Show("[GetChannelVolumeLevelScalar #1]: " + GetChannelVolumeLevelScalar(dataFlow, eRole, 1).ToString()); }
MessageBox.Show("[GetMasterVolumeLevelScalar]: " + GetMasterVolumeLevelScalar(dataFlow, eRole).ToString());
MessageBox.Show("[GetMute]: " + GetMute(dataFlow, eRole).ToString());
MessageBox.Show("[SetChannelVolumeLevelScalar #0]: 0.44"); SetChannelVolumeLevelScalar(dataFlow, eRole, 0, 0.44f);
if (channels > 1) { MessageBox.Show("[SetChannelVolumeLevelScalar #1]: 0.88"); SetChannelVolumeLevelScalar(dataFlow, eRole, 1, 0.88f); }
MessageBox.Show("[SetMasterVolumeLevelScalar]: 0.55"); SetMasterVolumeLevelScalar(dataFlow, eRole, 0.55f);
MessageBox.Show("[SetMute]: false"); SetMute(dataFlow, eRole, false);
}
}
///====================================================================================================
}
}
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