事件监听

事件监听

事件监听：当某个事情发生的时候，干什么？

package com.hua.demo;

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) {
        //按下按钮，触发一些事件
        Frame frame = new Frame();
        Button button = new Button();
        //因为，addActionListener()需要一个ActionListen，所以我们需要构造一个ActionListener
        ActionListener actionListener = new MyActionListener();
        button.addActionListener(actionListener);

        frame.add(button,BorderLayout.CENTER);
        frame.pack();

        windowClosing(frame);//关闭窗口
        frame.setVisible(true);
    }
    //关闭窗体的事件
    private  static void windowClosing(Frame frame){
        frame.addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
    }
}
//事件监听
class MyActionListener implements ActionListener{
    @Override
    public void actionPerformed(ActionEvent e) {
        System.out.println("aaa");
    }
}

多个按钮，共享一个事件

package com.hua.demo;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.rmi.activation.ActivationMonitor;

public class TestActionTwo {
    public static void main(String[] args) {
        //两个按钮实现同一个监听
        //开始 停止
        Frame frame = new Frame("开始-停止");

        Button button1 = new Button("start");
        Button button2 = new Button("stop");

        MyMonitor myMonitor = new MyMonitor();

        button2.setActionCommand("button2-stop");
        button1.addActionListener(myMonitor);
        button2.addActionListener(myMonitor);

        frame.add(button1,BorderLayout.NORTH);
        frame.add(button2,BorderLayout.SOUTH);

        frame.setVisible(true);
        frame.pack();
    }
}
class MyMonitor implements ActionListener {

    @Override
    public void actionPerformed(ActionEvent e) {
        //e.getActionCommand() 获得按钮的信息
        System.out.println("按钮被点击了：msg====>"+e.getActionCommand());
    }
}