Gdiplus :: Bitmap :: FromHBITMAP內存泄漏

Question

我反復調用此代碼，導致內存泄漏：

ULONG_PTR gdiplusToken;
int screen_height;
int screen_width;

CVCamStream::CVCamStream(HRESULT *phr, CVCam *pParent, LPCWSTR pPinName) : CSourceStream(LPCSTR(FILTER_NAME),phr, pParent, pPinName), m_pParent(pParent)
{
    hdc = GetDC(NULL);

    Gdiplus::GdiplusStartupInput gdiplusStartupInput;
    ULONG_PTR gdiplusToken;
    GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);

    screen_height = GetSystemMetrics(SM_CYVIRTUALSCREEN);
    screen_width = GetSystemMetrics(SM_CXVIRTUALSCREEN);
}

CVCamStream::~CVCamStream()
{
    Gdiplus::GdiplusShutdown(gdiplusToken);
    DeleteDC(hdc);
} 

HRESULT CVCamStream::FillBuffer(IMediaSample *pms)
{
    REFERENCE_TIME rtNow;
    REFERENCE_TIME avgFrameTime = ((VIDEOINFOHEADER*)m_mt.pbFormat)->AvgTimePerFrame;

    static clock_t refClock = clock();
    double elapsed = (clock() - refClock) / (double)CLOCKS_PER_SEC;

    rtNow = m_rtLastTime;
    m_rtLastTime += avgFrameTime;
    pms->SetTime(&rtNow, &m_rtLastTime);
    pms->SetSyncPoint(TRUE);

    HDC memdc = CreateCompatibleDC(NULL);

    CImage image;
    image.Create(screen_width, screen_height, 24);
    SelectObject(memdc, image);

    BYTE *pData;
    pms->GetPointer(&pData);
    long lDataLen = pms->GetSize();

    Gdiplus::Bitmap *bitmap = new Gdiplus::Bitmap(screen_width, screen_height, PixelFormat24bppRGB);

    BitBlt(memdc, 0, 0, screen_width, screen_height, hdc, 0, 0, SRCCOPY);
    DeleteDC(memdc);

    // memdc is already deleted
    bitmap->FromHBITMAP(image, NULL);

    delete bitmap;
    image.Destroy();
    DeleteObject(image);
    DeleteDC(memdc);

    return NOERROR;
} 

但是每次RAM使用量增加。 令人討厭的行是FromHBITMAP()函數，因為注釋它不再有泄漏。

我知道FromHBITMAP()創建了位圖的副本，但我想我釋放了所有的回憶！

怎么了

Answer 1

FromHBITMAP不擁有傳遞的位圖句柄的所有權。 您可以只傳遞仍由CImage實例擁有的位圖句柄。 同樣根據MSDN ：

不要將當前（或以前）選擇到設備上下文中的GDI位圖或GDI調色板傳遞給Bitmap :: FromHBITMAP方法。

當image仍被選擇進入memdc時，您正在調用它。