I've finally found out what was missing:
The Qt-Objects provide a method called winId(). This method returns a WId which actually is (on iOS) an UIView*.
You have to add that UIView* as Subview to your main view.
In order to achieve that I changed my createQtGUI method as follows:
WId createQtGUI() {
... // nothing changed here (only at the end)
window->show();
return window->winId();
}
And In my ViewController.mm (where I call my method):
- (IBAction)ButtonClicked:(id)sender {
UIView* newView = (__bridge UIView*)reinterpret_cast<void*>(createQtGUI());
[self.view addSubview:newView];
}
Note: The double cast (__bridge UIView*)reinterpret_cast<void*>(...) is necessary because you can't just cast from WId to UIView* in Objective-C++.
