Q_GUI_EXPORT HBITMAP qt_pixmapToWinHBITMAP(const QPixmap &p, int hbitmapFormat = 0);

声明这一句后, 就可以使用了

HBITMAP hBmp =  qt_pixmapToWinHBITMAP(pix, 2);

该函数定义在qpixmap_win.cpp下

还有一些其他的实用函数

Q_GUI_EXPORT QPixmap qt_pixmapFromWinHBITMAP(HBITMAP bitmap, int hbitmapFormat = 0);
Q_GUI_EXPORT HICON qt_pixmapToWinHICON(const QPixmap &p);
Q_GUI_EXPORT QImage qt_imageFromWinHBITMAP(HDC hdc, HBITMAP bitmap, int w, int h);
Q_GUI_EXPORT QPixmap qt_pixmapFromWinHICON(HICON icon);

Qt5.3中可以直接使用

在qtwinextras/qwinfunctions.h中

Q_WINEXTRAS_EXPORT HBITMAP toHBITMAP(const QPixmap &p, HBitmapFormat format = HBitmapNoAlpha);
Q_WINEXTRAS_EXPORT QPixmap fromHBITMAP(HBITMAP bitmap, HBitmapFormat format = HBitmapNoAlpha);