Using StretchDIBits() in QWidget

[bear101]

Hi

I've subclasses a QWidget because I want to perform my own drawing using Windows' StretchDIBits() function (I'm painting video frames). I've overwritten QWidget::paintEvent() where I'm doing my drawing like this:

void MyWidget::paintEvent(QPaintEvent *p)
{
    HWND hWnd = winId();
    HDC hdc;
    PAINTSTRUCT ps;
    hdc = BeginPaint(hWnd, &ps);
    BOOL b = StretchDIBits(hdc, 0, 0, rect().width(), rect().height(), 0, 0, 
                           bmh.biWidth, bmh.biHeight*-1, frm->frame, &bmi,
                           DIB_RGB_COLORS, SRCCOPY);
    EndPaint(hWnd, &ps);
}

void MyWidget::paintEvent(QPaintEvent *p)
{
    HWND hWnd = winId();
    HDC hdc;
    PAINTSTRUCT ps;
    hdc = BeginPaint(hWnd, &ps);
    BOOL b = StretchDIBits(hdc, 0, 0, rect().width(), rect().height(), 0, 0, 
                           bmh.biWidth, bmh.biHeight*-1, frm->frame, &bmi,
                           DIB_RGB_COLORS, SRCCOPY);
    EndPaint(hWnd, &ps);
}

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'bmh' is a BITMAPINFOHEADER and 'frm' is a byte-array of bitmap data.

When the paintEvent is called nothing is, however, shown. Why is this? When I use the above code in my MFC app it works fine (when I receive WM_PAINT).

-- Bjoern