单击JButton时如何在JWIndow上显示图像？

Question

I have a JMenuBar with a help button. When user clicks on "help" I need to open a different window with a .jpg showing the game instructions. That same window can be closed when the user clicks outside of it. I think I'm missing code because it does not work:

Window.java

public class Window extends JWindow
{
  //java.net.URL imgIntro = getClass().getResource("/images/intro.jpg");
  ImageIcon imIntro = new ImageIcon(getClass().getResource("/images/intro.jpg"));

  //java.net.URL imgRegles = getClass().getResource("/images/rules.jpg");
  ImageIcon imRules = new ImageIcon(getClass().getResource("/images/rules.jpg"));

  static Thread t = new Thread();
  static int thread = 0;
  static JButton bouton;
  static int X;
  static int Y;

  public Window( int X, int Y, int type) {

    super();
    Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
    setSize(X,Y);
    setLocation( (dim.width - X)/2 , (dim.height - Y)/2);
    setVisible(true);
    Container fen = getContentPane();

    if (type == 1 ) bouton = new JButton(imIntro);
    else            bouton = new JButton(imRules);

    bouton.setPreferredSize(new Dimension(X, Y) );
    fen.add( bouton);
    bouton.setVisible( true );

    show();


   /* if window introduction,
      just display for 5 secondes */

    if( type == 1 ) {
        try {
            Thread.sleep(5000);
            thread = 1;
        }
        catch( java.lang.InterruptedException ex ) {
            JOptionPane.showMessageDialog(null, "erreur");
            }
        dispose();

    }


    /* if window of rules
       only close it when user clicks */

    else if ( type == 2 ) {
        bouton.addActionListener( new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                     dispose();
                }
        });
    }

 }
}

Menu.java

    public class Menu extends JMenuBar implements ActionListener{

     Interface map;

            JMenu m5;

    public Menu(Interface map){
            super();
            this.map=map;
           m5 = new JMenu ("Help");//dislay instructions / rules

            this.add(m5);

    public void actionPerformed(ActionEvent evt){

//.../
                      else if(evt.getSource () == m5){
                          //new JWindow
                          Window rules = new Window( 700, 457, 2);

                      }
    }
    }

EDIT WITH MCVE

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.IOException;
import java.net.URISyntaxException;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;

/**
 *
 * @author Mark
 */
public class Test {



    JFrame mainFrame = new JFrame ();
    JFrame instructions = new JFrame();


    public Test (){
     gui ();
}


    public void gui (){
        mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        mainFrame.setSize(600, 400);
        mainFrame.setVisible(true);

        instructions.setSize(200, 200);

        JMenuBar mb = new JMenuBar ();
        JMenu help = new JMenu("Help");
        mb.add(help);
        JMenuItem instructionsMenu = new JMenuItem ("Instructions");
        help.add(instructions);


        mainFrame.setJMenuBar(mb);

        instructions.addActionListener(new ActionListener(){
            @Override

            public void actionPerformed(ActionEvent e){

                instructions.setVisible(true);
                mainFrame.dispose();
            }


        });


    }




    public static void main(String[] args) throws IOException, URISyntaxException
    {
        new Test ();
    }
}

Answer 1

I suggest you use a JDialog for the instructions window and not a JFrame . See here for example.

public class Test {

    JFrame mainFrame = new JFrame();
    JDialog instructions = new JDialog(mainFrame);

    public Test() {

        gui();
    }

    public void gui() {

        instructions.setSize(200, 200);

        JMenuBar mb = new JMenuBar();
        JMenu help = new JMenu("Help");
        mb.add(help);
        JMenuItem instructionsMenu = new JMenuItem("Instructions");
        help.add(instructionsMenu);
        instructionsMenu.addActionListener(e -> instructions.setVisible(true));

        mainFrame.setJMenuBar(mb);
        mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        mainFrame.setSize(600, 400);
        mainFrame.setVisible(true);
    }

    public static void main(String[] args) {

        SwingUtilities.invokeLater(() -> new Test());
    }
}

Notes:

• Call setVisible as the last thing you do for a window.
• In your real program, where you have components in the windows, call their pack() instead of setting their size.
• Start Swing from the EDT .

Answer 2

Why do you have a else-if condition without the if condition? This would create a syntax error.

Also, your code to show your window should be something like this:

dispose();
Window rules = new Window( 700, 457, 2);
rules.show();