Qt QML component like WPF HwndHost

Question

We have a desktop windows application that uses a component that needs a HWND to be displayed. In a WPF application we use a HwndHost to display it. We are trying to make a Qt QML based application to do the same.

Is it possible to host a HWND component in a QML application?

It works with a QQuickWindow, but the control I attach takes the entire window application area. I would like to bind to a smaller area, like the rectArea in the QML below. But a QQuickItem does not have a windId(), only its parent window(). It is possible?
Here is my QML:

ApplicationWindow {
  width: 640
  height: 480
  visible: true
  Rectangle {
    objectName: "rectArea"
    id: rectangle1
    x: 0
    y: 0
    width: 200
    height: 200
    color: "#ffffff"
 }
}

And here a cpp snippet:

void setHwnd(QQmlApplicationEngine& m_engine) {
  auto root_objects = m_engine.rootObjects();
  m_rootObject = root_objects[0];
  auto rect_area = m_rootObject->findChild<QQuickItem*>("rectArea");
  HWND hWnd = reinterpret_cast<HWND>(rect_area->window()->winId());
  // use hWnd here, but it takes the entire window area...
}

This is an interesting question. Can you tell us how did you eventually solve? — ceztko, Apr 11 '17 at 15:32

score 2 · Answer 1 · answered Apr 29 '15 at 21:38

2

Once you have a QWindow (or anything that inherits from it), you can obtain HWND by calling winId method. You will need to typecast it like this:

QWindow pWindow;
// create pWindow
HWND hWnd = reinterpret_cast<HWND>(pWindow->winId());

answered Apr 29 '15 at 21:38

seva titov

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score 0 · Answer 2 · answered Jun 12 '17 at 15:40

A Rectangle does not have its own HWND. You can only retrieve the HWND for the whole window. You have to restrict yourself to the rectangle are, e.g. when hosting a OpenGL application:

 glViewport(x(), windowHeight - y() - height(), width(), height());

Qt QML component like WPF HwndHost

2 Answers2