image based jframe become white when compute wake up from sleep mode or standby

Question

I have a JFrame with an image as background,called setUndecorated and setWindowOpaque method. When I open JFrame and then let computer sleep,but when computer wake up from sleep, the JFrame becomes white.

I guess it maybe repaint problem, but I can not solve this problem, would you please give me some suggestions?

Answer 1

You can simply try repainting the component, that contains the image when your window (JFrame) recieves focus. That should fix the problem of repainting after "waking up" i guess.

Also you can try this:

frame.addWindowListener ( new WindowAdapter ()
{
    public void windowActivated ( WindowEvent e )
    {
        // Here repaint what you need
    }
} );