I\'m trying to use the method described here to use a QPainter and GDI calls on the same widget.
Unfortunately this tutorial seem to have been written on an earlier version
I got this working in QT 4.7-beta 2 as follows
Use the following code in the paintEvent();
QPainter painter(this);
HDC hdc = painter.paintEngine()->getDC(); // THIS IS THE CRITICAL STEP!
HWND hwnd = winID();
// From this point on it is all regular GDI
QString text("Test GDI Paint");
RECT rect;
GetClientRect(hwnd, &rect);
HBRUSH hbrRed = CreateSolidBrush(RGB(255,0,0));
FillRect(hdc, &rect, hbrRed);
HBRUSH hbrBlue = CreateSolidBrush(RGB(40,40,255));
HPEN bpenGreen = CreatePen(PS_SOLID, 4, RGB(0,255,0));
SelectObject(hdc,bpenGreen);
SelectObject(hdc,hbrBlue);
Ellipse(hdc,10,10,rect.right-20,rect.bottom-20);
SetTextAlign(hdc, TA_CENTER | TA_BASELINE);
TextOutW(hdc, width() / 2, height() / 2, text.utf16(), text.size());
ReleaseDC(hwnd, hdc);
This worked with Qt 4.0 and 4.1, but stopped working in either 4.2 or 4.3, when Trolltech reimplemented the Windows paint engine. In the second edition of the Qt 4 book, we added the sentence:
"For this to work, we must also reimplement QPaintDevice::paintEngine() to return a null pointer and set the Qt::WA_PaintOnScreen attribute in the widget's constructor."
I haven't tested it using later versions of Qt (I'm no longer at Trolltech/Nokia and have no Windows machine) but I hope it will still work.