GUI事件监听

事件监听

• 事件监听：当某个事情发生时，干什么？
• 当按下按钮，在控制台输出aaaaa
• 当按下X，关闭窗口

package com.yuecheng.lesson01;

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

public class A1 {
    public static void main(String[] args) {
        Frame frame = new Frame();
        frame.setVisible(true);
        frame.setSize(500,500);
        //按下按钮触发一些事件
        Button button = new Button("玥骋说：");
        //按钮要触发的事件，因为这里需要ActionListener，要构造一个ActionListener
        A2 a2 = new A2();
        button.addActionListener(a2);
        frame.add(button, BorderLayout.NORTH);


        windowclose(frame);
    }
    private static void windowclose(Frame frame){
        frame.addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
    }
}
//事件监听
class A2 implements ActionListener{
    @Override
    public void actionPerformed(ActionEvent e) {
        System.out.println("肖婉茹大笨蛋");
    }
}

两个按钮共享一个事件

package com.yuecheng.lesson01;

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

public class A3 {

    public static void main(String[] args) {

        Frame frame = new Frame();
        frame.setLayout(new GridLayout(2,1));

        Button button = new Button("xiao");
        Button button2 = new Button("wan");

        A4 a4 = new A4();
        button2.addActionListener(a4);
        button.addActionListener(a4);
        //这里会覆盖默认信息使s2变成下面这句话,如果不调用，就会返回默认
        button2.setActionCommand("肖婉茹说");
        frame.add(button);
        frame.add(button2);
        frame.pack();
        frame.setVisible(true);
        frame.setBounds(0,0,500,500);

    }
}
class A4 implements ActionListener{
    @Override
    public void actionPerformed(ActionEvent e) {
        //这里的事件被调用后，必然发生
        //e.getActionCommand()获取信息
        System.out.println(e.getActionCommand()+"她爱我");
    }
}