Alternative of cvGetWindowHandle() in opencv4+

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Hi. I am using Opencv3.4.8 in my MFC application. I am using cvGetWindowHandle() to get the handle of the window as follows;

namedWindow(windowname, WINDOW_AUTOSIZE);
HWND hWnd = (HWND) cvGetWindowHandle(windowname.c_str());
HWND hParent = ::GetParent(hWnd);
::SetParent(hWnd, GetDlgItem(IDC_PICTURE)->m_hWnd);
::ShowWindow(hParent, SW_HIDE);
CWnd* pWnd = new CWnd();
pWnd->CWnd::Attach(hParent);

Now I want to upgrade to Opencv4+ and there is no cvGetWindowHandle() in Opencv4+. I want to know if there is an alternative function in Opencv4+ and if not how can I do the same task in opencv4+.

Thanks.