test.java

点击菜单可弹出~子菜单

import java.awt.Component;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

public class Test extends JFrame implements ActionListener{
    public Test(){
        setSize(200,400);
        setLayout(null);
        JPanel p = new JPanel();
        p.setBounds(10,10,80,350);
        add(p);
        p.setLayout(new GridBagLayout());
        Insets is = new Insets(1,1,1,1);
        JButton b = new JButton("test 1");
        p.add(b,new GridBagConstraints(0,0,1,1,1,0,GridBagConstraints.WEST,GridBagConstraints.HORIZONTAL,is,0,0));
        b.addActionListener(this);
        b = new JButton("sub test 11");
        b.setVisible(false);
        p.add(b,new GridBagConstraints(0,1,1,1,1,0,GridBagConstraints.WEST,GridBagConstraints.HORIZONTAL,is,0,0));
        b = new JButton("sub test 12");
        b.setVisible(false);
        p.add(b,new GridBagConstraints(0,2,1,1,1,0,GridBagConstraints.WEST,GridBagConstraints.HORIZONTAL,is,0,0));
        b = new JButton("sub test 13");
        b.setVisible(false);
        p.add(b,new GridBagConstraints(0,3,1,1,1,0,GridBagConstraints.WEST,GridBagConstraints.HORIZONTAL,is,0,0));
        b = new JButton("test 2");
        b.addActionListener(this);
        p.add(b,new GridBagConstraints(0,4,1,1,1,0,GridBagConstraints.WEST,GridBagConstraints.HORIZONTAL,is,0,0));
        b = new JButton("sub test 21");
        p.add(b,new GridBagConstraints(0,5,1,1,1,0,GridBagConstraints.WEST,GridBagConstraints.HORIZONTAL,is,0,0));
        b.setVisible(false);
        b = new JButton("sub test 22");
        p.add(b,new GridBagConstraints(0,6,1,1,1,0,GridBagConstraints.WEST,GridBagConstraints.HORIZONTAL,is,0,0));
        b.setVisible(false);
        b = new JButton("sub test 23");
        b.setVisible(false);
        p.add(b,new GridBagConstraints(0,7,1,1,1,0,GridBagConstraints.WEST,GridBagConstraints.HORIZONTAL,is,0,0));
        b = new JButton("exit");
        b.addActionListener(this);
        p.add(b,new GridBagConstraints(0,8,1,1,1,0,GridBagConstraints.WEST,GridBagConstraints.HORIZONTAL,is,0,0));
        JLabel lb = new JLabel();
        p.add(lb,new GridBagConstraints(0,9,1,1,1,1,GridBagConstraints.WEST,GridBagConstraints.BOTH,is,0,0));
    }
    public void actionPerformed(ActionEvent e){
        JButton b = (JButton)e.getSource();
        if(b.getText().equals("test 1")){
            Component[] objects = b.getParent().getComponents();
            for(int i=0;i<objects.length;i++){
                if( objects[i] instanceof JButton){
                    JButton bt = (JButton)objects[i];
                    if ( bt.getText().startsWith("sub test 1")){
                        bt.setVisible(!bt.isVisible());
                    }else if ( bt.getText().startsWith("sub test 2")){
                        bt.setVisible(false);
                    }
                }
            }
        }else if(b.getText().equals("test 2")){
            Component[] objects = b.getParent().getComponents();
            for(int i=0;i<objects.length;i++){
                if( objects[i] instanceof JButton){
                    JButton bt = (JButton)objects[i];
                    if ( bt.getText().startsWith("sub test 2")){
                        bt.setVisible(!bt.isVisible());
                    }else if ( bt.getText().startsWith("sub test 1")){
                        bt.setVisible(false);
                    }
                }
            }
        }else if(b.getText().equals("exit")){
            System.exit(0);
        }
    }
    public static void main(String[] args){
        Test t = new Test();
        t.setVisible(true);
    }
}