2.4 事件監聽

事件監聽：當某個事件發生的時候，幹什麼？

package com.GGp.lesson02;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

public class TestActionEvent {
    public static void main(String[] args) {
        Frame frame = new Frame();
        frame.setVisible(true);
        frame.setSize(300,300);
        //按下按鈕，觸發一些事件
        Button button = new Button("button");
        button.setSize(100,100);
        button.setBackground(Color.red);

        //因為addActionListener()，需要一個ActionListener，
        //所以才去構造一個ActionListener
        MyActionListener myActionListener = new MyActionListener();
        button.addActionListener(myActionListener);
        frame.add(button);

        frame.addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
    }
}
//事件監聽
class MyActionListener implements ActionListener {

    @Override
    public void actionPerformed(ActionEvent e) {
        System.out.println("你按了一次哦");
    }
}