我不确定在一个函数中使用CComPtr的方法,该函数有一个表示为双指针的参数:
HRESULT D3DPresentEngine::CreateD3DSample(
IDirect3DSwapChain9 *pSwapChain,
IMFSample **ppVideoSample
)
{
// Caller holds the object lock.
D3DCOLOR clrBlack = D3DCOLOR_ARGB(0xFF, 0x00, 0x00, 0x00);
CComPtr< IDirect3DSurface9 > pSurface;
CComPtr< IMFSample > pSample;
// Get the back buffer surface.
ReturnIfFail( pSwapChain->GetBackBuffer(0, D3DBACKBUFFER_TYPE_MONO, &pSurface ) );
// Fill it with black.
ReturnIfFail( m_pDevice->ColorFill(pSurface, NULL, clrBlack));
// Create the sample.
ReturnIfFail( MFCreateVideoSampleFromSurface(pSurface, &pSample));
// Return the pointer to the caller.
*ppVideoSample = pSample;
(*ppVideoSample)->AddRef();
return S_OK;
}
我对最后一次分配AddRef调用有疑问.
他们对你好吗?
提前致谢
解决方法:
没关系,但可以简化:
HRESULT D3DPresentEngine::CreateD3DSample(
IDirect3DSwapChain9 *pSwapChain,
IMFSample **ppVideoSample
)
{
// Caller holds the object lock.
D3DCOLOR clrBlack = D3DCOLOR_ARGB(0xFF, 0x00, 0x00, 0x00);
CComPtr< IDirect3DSurface9 > pSurface;
// Get the back buffer surface.
ReturnIfFail( pSwapChain->GetBackBuffer(0, D3DBACKBUFFER_TYPE_MONO, &pSurface ) );
// Fill it with black.
ReturnIfFail( m_pDevice->ColorFill(pSurface, NULL, clrBlack));
// Create the sample.
ReturnIfFail( MFCreateVideoSampleFromSurface(pSurface, ppVideoSample));
return S_OK;
}
在您的代码中,AddRef是必需的,因为当PSample超出范围时,它将释放.