一、關於佈局管理器：

package Layout;

import java.awt.*;

import javax.swing.*;

public class BorderLayoutEx extends JFrame{

        private JButton northButton;
        private JButton southButton;
        private JButton eastButton;
        private JButton westButton;
        private JButton centerButton;
        private
 
 FlowLayout layout;

        public BorderLayoutEx(){
            setTitle("邊佈局管理器");
            setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            setSize(640,480);
            Container cp = getContentPane();
            layout = new FlowLayout(FlowLayout.LEFT);
            cp.setLayout(layout);
            northButton = new
 
 JButton("North");
            southButton = new JButton("south");
            eastButton = new JButton("east");
            westButton = new JButton("west");
            centerButton = new JButton("center");
//          cp.add(northButton,BorderLayout.NORTH);
//          cp.add(southButton, BorderLayout.SOUTH);
 

//          cp.add(eastButton, BorderLayout.EAST);
//          cp.add(westButton, BorderLayout.WEST);
//          cp.add(centerButton,BorderLayout.CENTER);

            cp.add(northButton);
            cp.add(southButton);
            cp.add(eastButton);
            cp.add(westButton);
            cp.add(centerButton);

        }
        public static void main(String arg[]){
            BorderLayoutEx Bl = new BorderLayoutEx();
            Bl.setVisible(true);

        }
}

流佈局管理器效果：

邊佈局管理器：

二、變色應用（事件監聽器）

package Layout;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.*;

public class C9_5 extends JFrame{
    private JLabel label;
    private JButton red;
    private JButton yellow;
    private JButton blue;
    private JButton green;
    public C9_5(){
        setTitle("變色");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setSize(400,400);
        label = new JLabel("");
        label.setFont(new Font("",1,30));
        label.setHorizontalAlignment(label.CENTER);
        red = new JButton("紅色");
        red.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e) {
                label.setForeground(Color.RED);
                label.setText("紅色");
            }
        });
        yellow = new JButton("黃色");
        yellow.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e) {
                label.setForeground(Color.yellow);
                label.setText("黃色");
            }

        });
        blue = new JButton("藍色");
        blue.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e) {
                label.setForeground(Color.BLUE);
                label.setText("藍色");
            }

        });
        green = new JButton("綠色");
        green.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e) {
                label.setForeground(Color.green);
                label.setText("綠色");
            }

        });
        Container cp = getContentPane();
        cp.add(label,BorderLayout.CENTER);
        cp.add(blue,BorderLayout.EAST);
        cp.add(yellow,BorderLayout.SOUTH);
        cp.add(red,BorderLayout.WEST);
        cp.add(green,BorderLayout.NORTH);
    }

    public static void main(String arg[])
    {
        C9_5 test = new C9_5();
        test.setVisible(true);
    }

}

效果：