Qt窗体引用window自带阴影边框效果

<1>.工程pro文件添加Dwmapi.lib

LIBS += Dwmapi.lib

<2>.窗体控件添加系统函数

#ifdef Q_OS_WIN  
#include <Dwmapi.h>  // Use system shadow frame
#endif

TMainWindow::TMainWindow(QDialog *parent) 
    : QDialog(parent)
{
#ifdef Q_OS_WIN 
    BOOL bEnable = false;
    ::DwmIsCompositionEnabled(&bEnable);
    if (bEnable)
    {
        DWMNCRENDERINGPOLICY ncrp = DWMNCRP_ENABLED;
        ::DwmSetWindowAttribute((HWND)winId(), DWMWA_NCRENDERING_POLICY, &ncrp, sizeof(ncrp));
        MARGINS margins = { -1 };
        ::DwmExtendFrameIntoClientArea((HWND)winId(), &margins);
    }
#endif    
}

<3>.边框拖拽功能

#define MWS_SYS_DRAG_WIDTH 4      //边框响应鼠标间距
#define FRAME_MINI_WIDTH   1024   //窗体默认最小宽度
#define FRAME_MINI_HEIGHT  768    //窗体默认最小高度
bool TMainWindow::nativeEvent(const QByteArray &eventType, void *message, long *result)
{
#ifdef Q_OS_WIN
    MSG *msg = reinterpret_cast<MSG*>(message);
    switch (msg->message)
    {
        case WM_NCHITTEST:
        {
            QPoint p   = mapFromGlobal(QCursor::pos());
            int xPos   = p.x();
            int yPos   = p.y();
            int nHeigh = height();
            int nWidth = width();

            *result = HTNOWHERE;

            if (!isFullScreen() && !isMaximized())
            {
                if (xPos >= 0 && xPos < MWS_SYS_DRAG_WIDTH){
                    if (yPos >= 0 && yPos < MWS_SYS_DRAG_WIDTH)
                    {
                        *result = HTTOPLEFT;
                    }
                    else if (yPos >= (nHeigh - MWS_SYS_DRAG_WIDTH) && yPos <= nHeigh)
                    {
                        *result = HTBOTTOMLEFT;
                    }
                    else
                    {
                        *result = HTLEFT;
                    }
                }

                if (xPos >= nWidth - MWS_SYS_DRAG_WIDTH && xPos <= nWidth)
                {
                    if (yPos >= 0 && yPos <= MWS_SYS_DRAG_WIDTH)
                    {
                        *result = HTTOPRIGHT;
                    }
                    else if (yPos >= (nHeigh - MWS_SYS_DRAG_WIDTH) && yPos <= nHeigh)
                    {
                        *result = HTBOTTOMRIGHT;
                    }
                    else
                    {
                        *result = HTRIGHT;
                    }
                }

                if (xPos >= MWS_SYS_DRAG_WIDTH && xPos < nWidth - MWS_SYS_DRAG_WIDTH
                    && yPos > 0 && yPos < MWS_SYS_DRAG_WIDTH)
                {
                    *result = HTTOP;
                }

                if (xPos > MWS_SYS_DRAG_WIDTH && xPos < nWidth - MWS_SYS_DRAG_WIDTH
                    && yPos >(nHeigh - MWS_SYS_DRAG_WIDTH) && yPos < nHeigh)
                {
                    *result = HTBOTTOM;
                }
            }
            if (HTNOWHERE == *result)
            {
                return false;
            }
            return true;
        }
        break;

        case WM_GETMINMAXINFO:
        {
            MINMAXINFO *mmi = (MINMAXINFO*)(msg->lParam);

            QRect desktop     = qApp->desktop()->availableGeometry(this);
            QRect desktopRect = qApp->desktop()->screenGeometry(this);

            mmi->ptMaxSize.x = desktop.width();
            mmi->ptMaxSize.y = desktop.height();

            int desktopLeft = desktop.left() - desktopRect.left();
            int desktopTop  = desktop.top() - desktopRect.top();

            mmi->ptMaxPosition.x = desktopLeft;
            mmi->ptMaxPosition.y = desktopTop;

            mmi->ptMinTrackSize.x = FRAME_MINI_WIDTH;
            mmi->ptMinTrackSize.y = FRAME_MINI_HEIGHT;

            mmi->ptMaxTrackSize.x = desktop.width();
            mmi->ptMaxTrackSize.y = desktop.height();

            result = 0;

            return true;
        }
        break;

        case WM_SIZE:
            switch (msg->wParam)
            {
            case SIZE_MAXIMIZED:
                break;
            case SIZE_RESTORED:
                break;
            }
            break;
    }
    return QWidget::nativeEvent(eventType, message, result);
#else
    return QWidget::nativeEvent(eventType, message, result);    
#endif
}