Create new thread for a new JFrame

Question

I'm learning about threads and I've got a problem with it. I'm trying to make 2 frames, one is a main frame and another will be shown later after clicking on a button. I want to stop the main frame while the new frame is running. Can you guys help me with a very simple example for this? (And the new frame will be closed after clicking on a button too). Just 2 frames with a button on each are enough. Much appreciated!

Answer 1

You should avoid the use of multiple JFrames, use modal dialogs instead. JOptionPane offers a ton of good, easy & flexible methods to do so.

Here's an example. When you click the button the dialog will appear on top of the JFrame. The main JFrame won't be clickable anymore, since JOptionPane.showMessageDialog() produces a modal window.

import java.awt.EventQueue;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;

public class Example {

    public Example() {

        JFrame frame = new JFrame();

        JButton button = new JButton("Click me");
        button.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent arg0) {
                JOptionPane.showMessageDialog(frame, "I'm a dialog!");
            }
        });

        frame.getContentPane().setLayout(new FlowLayout());
        frame.getContentPane().add(button);

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);

    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                new Example();
            }
        });
    }


}

Output: