QMenu appears under fullscreen MainWindow on Windows (works on Ubuntu)

FDK2099

Hi Qt community,

I’m working on a QMainWindow in fullscreen mode (Qt::WindowFullScreen) and want to open a context menu from a keyboard shortcut.

Here is a simplified code:

void Factory::createSampleMenu()
{
    QMenu *menu = new QMenu(); // tried with/without parent
    menu->addAction("Action 1");
    menu->addAction("Action 2");

    QPoint pos = QCursor::pos();
    menu->exec(pos); // also tried popup()
}

Behavior:

On Ubuntu (X11/Wayland): menu shows above fullscreen window correctly.
On Windows 10/11: menu appears under fullscreen window (invisible).

Things I tried:

Qt::Popup, Qt::Tool, Qt::WindowStaysOnTopHint
With/without parent (_mainWindow or nullptr)
Both exec() and popup()

But the menu is still hidden below the fullscreen window.

Questions:

Is this a known limitation of Windows with Qt popups in fullscreen?
Is there a Qt-only workaround to make QMenu float above a fullscreen QMainWindow?
Or is the only option to use native WinAPI (SetWindowPos(HWND_TOPMOST, ...))?

Environment:

Qt 5.x
Windows 10
Works fine on Ubuntu

Any advice, workarounds, or best practices would be greatly appreciated.

SGaist

Hi and welcome to devnet,

Which version of Qt 5 exactly ?
Do you have the same issue if you use Qt 6 ?

FDK2099

@SGaist said in QMenu appears under fullscreen MainWindow on Windows (works on Ubuntu):

Hi and welcome to devnet,

Which version of Qt 5 exactly ?
Do you have the same issue if you use Qt 6 ?

Hi
I’m currently using Qt 5.15.2 on Windows 10.

I need to continue my project with Qt 5, and at the moment I don’t have the possibility to switch versions to check whether it works correctly with Qt 6.