ui中新增一個MDI Area控制元件mdiArea
標頭檔案新增#include <Windows.h>並且新增#pragma comment(lib, "user32.lib")或是pro檔案新增LIBS += -luser32

    Mat src = imread("F:/LearningOpenCV/pictures/1.jpg", 0);
    namedWindow("src",0);
    HWND hwnd = ::FindWindowW(NULL, L"src");
    QWindow* native_wnd  = QWindow::fromWinId((WId)hwnd);
    QWidget* native_wdgt = QWidget::createWindowContainer(native_wnd);
    ui->mdiArea->addSubWindow(native_wdgt);
    imshow("src"
 
, src);
    native_wdgt->setMinimumSize(600,400);

不要加waitKey(0);