How to show the fileDialog window on top of all windows

[ChiaoHuang]

Hi everyone,
I use QT 5.6.3 now.
I'd like to create a QT application on my board.
It should be full screen and no weston toolbar.
Therefore, I add this to MainWindow::MainWindow function.

    ui->setupUi(this);
    setWindowFlags(Qt::Window);
    showFullScreen();

I'd like to use QFileDialog to select files.
When it shows the fileDialog window, the weston toolbar will display also.
like this:

When I touch the MainWindow part, the fileDialog window will disappear.

I have two questions.

1. How to show the fileDialog window and no weston toolbar?
2. How to show the fileDialog window on top of all windows?

Thanks

[sierdzio]

1. I don't know.
2. You need to set the dialog to be "ApplicationModal" or set "modal" property: https://doc.qt.io/qt-5/qdialog.html#modal-prop