exec 67 JDialog

import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
public class Exec67 extends JFrame implements ActionListener{
    JDialog win1,win2;
    public Exec67() {
        setTitle("Test");
        setSize(400,400);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLocationRelativeTo(null);
        
        JMenuBar bar = new JMenuBar();
        JMenuItem menu1 = new JMenuItem("正方形");
        JMenuItem menu2 = new JMenuItem("三角形");
        menu1.addActionListener(this);
        menu2.addActionListener(this);
        setJMenuBar(bar);
        bar.add(menu1);bar.add(menu2);
        
        win1 = new JDialog(this,true);
        win1.setLayout(new FlowLayout());
        win1.setSize(200,200);
        win1.setTitle("正方形");
        win1.setLocationRelativeTo(this);
        win1.add(new JLabel("输入边长:"));
        final JTextField input = new JTextField(6);
        final JTextField result = new JTextField(6);
        result.setEditable(false);
        win1.add(input);
        win1.add(new JLabel("计算结果:"));
        win1.add(result);
        JButton bt = new JButton("计算");
        bt.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e){
                double r = Double.valueOf(input.getText());
                result.setText(String.format("%.3f", r*r));
            }
        });
        win1.add(bt);
        
        win2 = new JDialog(this,false);
        win2.setSize(200,200);
        win2.setLocationRelativeTo(this);
        win2.add(new JLabel("TEST TEST"));
    
    }

    /**
     * @param args
     */
    public static void main(String[] args) {
        new Exec67().setVisible(true);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        JMenuItem menu = (JMenuItem)(e.getSource());
        if (menu.getActionCommand().equals("正方形")) {win1.setVisible(true);win1.pack();}
        else win2.setVisible(true);
    }

}