C#DirectSound DirectSoundBuffer.SetVolume E#u NOINTERFACE

我正在为我的音频库编写DirectSound包装。 我遇到了directsound，它工作得很好。这意味着音频回放的效果比waveout等要好得多。 但现在我有一个问题。 我正在尝试设置secondarybuffer的音量。 我得到一个例外，因为我的接口无法转换或类似的东西，所以存在HResult E_NOINTERFACE。这怎么可能呢。我有Setvolume方法的代码：void Setvolume（int lVolume）

我正在将值-56传递给它

下面是确切的错误消息：

类型为“System.\u ComObject”的COM对象无法转换为接口类型“AMEngine.DX.IDirectSoundBuffer”。无法执行此操作，因为无法执行因错误而对IID“{279AFA85-4981-11CE-A521-0020AF0BE560}”接口的COM组件的QueryInterface调用：不支持此类接口（HRESULT的异常：0x80004002（E_NOINTERFACE））

我翻译了这个：

DEFINE_GUID(IID_IDirectSoundBuffer, 0x279AFA85, 0x4981, 0x11CE, 0xA5, 0x21, 0x00, 0x20, 0xAF, 0x0B, 0xE5, 0x60);

#undef INTERFACE
#define INTERFACE IDirectSoundBuffer
   DECLARE_INTERFACE_(IDirectSoundBuffer, IUnknown)
{
    STDMETHOD(QueryInterface)       (THIS_ __in REFIID, __deref_out LPVOID*) PURE;
    STDMETHOD_(ULONG,AddRef)        (THIS) PURE;
    STDMETHOD_(ULONG,Release)       (THIS) PURE;
    STDMETHOD(GetCaps)              (THIS_ __out LPDSBCAPS pDSBufferCaps) PURE;
    STDMETHOD(GetCurrentPosition)   (THIS_ __out_opt LPDWORD pdwCurrentPlayCursor, __out_opt LPDWORD pdwCurrentWriteCursor) PURE;
    STDMETHOD(GetFormat)            (THIS_ __out_bcount_opt(dwSizeAllocated) LPWAVEFORMATEX pwfxFormat, DWORD dwSizeAllocated, __out_opt LPDWORD pdwSizeWritten) PURE;
    STDMETHOD(GetVolume)            (THIS_ __out LPLONG plVolume) PURE;
    STDMETHOD(GetPan)               (THIS_ __out LPLONG plPan) PURE;
    STDMETHOD(GetFrequency)         (THIS_ __out LPDWORD pdwFrequency) PURE;
    STDMETHOD(GetStatus)            (THIS_ __out LPDWORD pdwStatus) PURE;
    STDMETHOD(Initialize)           (THIS_ __in LPDIRECTSOUND pDirectSound, __in LPCDSBUFFERDESC pcDSBufferDesc) PURE;
    STDMETHOD(Lock)                 (THIS_ DWORD dwOffset, DWORD dwBytes,
                                           __deref_out_bcount(*pdwAudioBytes1) LPVOID *ppvAudioPtr1, __out LPDWORD pdwAudioBytes1,
                                           __deref_opt_out_bcount(*pdwAudioBytes2) LPVOID *ppvAudioPtr2, __out_opt LPDWORD pdwAudioBytes2, DWORD dwFlags) PURE;
    STDMETHOD(Play)                 (THIS_ DWORD dwReserved1, DWORD dwPriority, DWORD dwFlags) PURE;
    STDMETHOD(SetCurrentPosition)   (THIS_ DWORD dwNewPosition) PURE;
    STDMETHOD(SetFormat)            (THIS_ __in LPCWAVEFORMATEX pcfxFormat) PURE;
    STDMETHOD(SetVolume)            (THIS_ LONG lVolume) PURE;
    STDMETHOD(SetPan)               (THIS_ LONG lPan) PURE;
    STDMETHOD(SetFrequency)         (THIS_ DWORD dwFrequency) PURE;
    STDMETHOD(Stop)                 (THIS) PURE;
    STDMETHOD(Unlock)               (THIS_ __in_bcount(dwAudioBytes1) LPVOID pvAudioPtr1, DWORD dwAudioBytes1,
                                           __in_bcount_opt(dwAudioBytes2) LPVOID pvAudioPtr2, DWORD dwAudioBytes2) PURE;
    STDMETHOD(Restore)              (THIS) PURE;
};

进入

音量是用以下代码设置的：（我传递的值是-56）no sound=0和maxsound=-10000

        private void SetCurrentVolume()
    {
        if (secondaryBuffer != null)
        {
            secondaryBuffer.SetVolume(volume);
        }
    }

---

E_NOINTERFACE

错误很简单：用于查询另一个接口的接口指针无法提供给您。也就是说，您（或者您正在使用的库）正在从非缓冲区对象的对象中提取代码。

IDirectSoundBuffer

。如果您在错误位置周围发布代码片段，这将非常有用。

可能是线程问题。很难说，没有人可以从异常消息中对代码进行反向工程。

 DSBufferDescription secondaryBufferDesc = new DSBufferDescription();
        secondaryBufferDesc.dwBufferBytes = (uint)(bufferSize * 2);
        //http://msdn.microsoft.com/en-us/library/windows/desktop/microsoft.directx_sdk.reference.dsbcaps%28v=vs.85%29.aspx
        secondaryBufferDesc.dwFlags = DirectSoundBufferCaps.DSBCAPS_CTRLVOLUME |
                                      DirectSoundBufferCaps.DSBCAPS_CTRLPOSITIONNOTIFY |
                                      DirectSoundBufferCaps.DSBCAPS_GETCURRENTPOSITION2 |
                                      DirectSoundBufferCaps.DSBCAPS_GLOBALFOCUS |
                                      DirectSoundBufferCaps.DSBCAPS_STICKYFOCUS;
        secondaryBufferDesc.dwReserved = 0;
        secondaryBufferDesc.dwSize = Marshal.SizeOf(secondaryBufferDesc);
        secondaryBufferDesc.guid3DAlgorithm = Guid.Empty;
        secondaryBufferDesc.guid3DAlgorithm = Guid.Empty;

        Wave.WaveFormat format = new Wave.WaveFormat(waveFormat, waveFormat.SampleRate);
        GCHandle lpwfxSecondaryPtr = GCHandle.Alloc(format, GCHandleType.Pinned);
        secondaryBufferDesc.lpwfxFormat = lpwfxSecondaryPtr.AddrOfPinnedObject();
        //IntPtr waveFormatPtr = Marshal.AllocHGlobal(Marshal.SizeOf(waveFormat));
        //Marshal.StructureToPtr(waveFormat, waveFormatPtr, false);
        //secondaryBufferDesc.lpwfxFormat = waveFormatPtr;

        object primaryBufferObj, secondaryBufferObj;
        //http://msdn.microsoft.com/en-us/library/windows/desktop/microsoft.directx_sdk.idirectsound8.idirectsound8.createsoundbuffer%28v=vs.85%29.aspx
        directSound.CreateSoundBuffer(primaryBufferDesc, out primaryBufferObj, IntPtr.Zero);
        directSound.CreateSoundBuffer(secondaryBufferDesc, out secondaryBufferObj, IntPtr.Zero);

        lpwfxSecondaryPtr.Free();

        this.primaryBuffer = (IDirectSoundBuffer)primaryBufferObj;
        this.secondaryBuffer = (IDirectSoundBuffer)secondaryBufferObj;

        private void SetCurrentVolume()
    {
        if (secondaryBuffer != null)
        {
            secondaryBuffer.SetVolume(volume);
        }
    }