将JMenuBar和JPanel添加到JFrame

Question

I am having some trouble with adding a JMenuBar and a JPanel to a JFrame, here is my Main Method:

public static Timer timer = new Timer(100, ActionListener.repaint);


public static void main(String[] args) {
    Insets in;
    frame.setSize(600, 500);
    frame.pack();
    in = frame.getInsets();
    frame.setSize(600 + (in.left + in.right) - 10, 500 + (in.top + in.bottom) - 10);
    frame.setResizable(false);

    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setLocationRelativeTo(null);
    add.addActionListener(new ActionListener());
    frame.setJMenuBar(menuBar);


    menuBar.add(file);
    file.add(add);
    file.add(sub);

    frame.add(gui);
    timer.start();

    frame.setVisible(true);
}

The field 'gui' is my JPanel class:

@Override
public void paintComponent(Graphics g) {


}

Here is my repaint Timer:

public static java.awt.event.ActionListener repaint = new java.awt.event.ActionListener() {

    @Override
    public void actionPerformed(ActionEvent e) {
        GUI.gui.repaint();
    }
};

here is the output:

See how it duplicated the JMenuBar? It does that for anything painted onto that JPanel. Any solutions?

Answer 1

Any solutions?

Yes. Dont call Thread.sleep in the paintComponent method. In fact dont call Thread.sleep anywhere in a Swing application. For periodic delays use a Swing Timer