事件监听一

/**

* 事件处理机制

* 1、组件

* 2、键盘

* 3、鼠标

* 4、窗口

* ActionListener事件监听

*/package java8_1;

import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

public class java8_3 extends JFrame implements ActionListener{

myPanel3 pan3=null;

JButton an1,an2;

public static void main(String[]args){

new java8_3();

}

{

pan3=new myPanel3();

an1=new JButton("红色");

an2=new JButton("蓝色");

Jtz jt1=new Jtz();

this.add(an1,BorderLayout.NORTH);

this.add(an2,BorderLayout.SOUTH);

pan3.setBackground(Color.PINK);

this.add(pan3);

an1.addActionListener(this);

an1.addActionListener(jt1);

an1.setActionCommand("111");

//区别按钮

an2.addActionListener(this);

an2.addActionListener(jt1);

an2.setActionCommand("222");

this.setSize(300,260);

this.setLocation(300, 280);

this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

this.setVisible(true);

}

public void actionPerformed(ActionEvent e){

// System.out.println("按钮起作用了");

if(e.getActionCommand().equals("111")){

//System.out.println("红色红色");

pan3.setBackground(Color.red);

}else if(e.getActionCommand().equals("222")){

//System.out.println("蓝色蓝色");

pan3.setBackground(Color.BLUE);

}

}

}

class myPanel3 extends JPanel{

public void paint(Graphics g){

super.paint(g);

g.drawString("南海是中国的！", 100, 150);

}

}

class Jtz implements ActionListener{

public void actionPerformed(ActionEvent aa){

if(aa.getActionCommand().equals("111")){

System.out.println("监听者在监听，知道你按下的是红色按钮");

}else {

System.out.println("监听者在监听，知道你按下的是蓝色按钮");

}

}

}

<span style="font-size:24px;">/**
* 事件处理机制
* 1、组件
* 2、键盘
* 3、鼠标
* 4、窗口
* ActionListener事件监听
*/package java8_1;
import java.awt.*;
import java.awt.event.*;

import javax.swing.*;
public class java8_3 extends JFrame implements ActionListener{

myPanel3 pan3=null;
JButton an1,an2;
public static void main(String[]args){
new java8_3();
}
{

pan3=new myPanel3();
an1=new JButton("红色");
an2=new JButton("蓝色");
Jtz jt1=new Jtz();

this.add(an1,BorderLayout.NORTH);
this.add(an2,BorderLayout.SOUTH);
pan3.setBackground(Color.PINK);
this.add(pan3);
an1.addActionListener(this);
an1.addActionListener(jt1);
an1.setActionCommand("111");
//区别按钮
an2.addActionListener(this);
an2.addActionListener(jt1);
an2.setActionCommand("222");

this.setSize(300,260);
this.setLocation(300, 280);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
}

public void actionPerformed(ActionEvent e){
// System.out.println("按钮起作用了");
if(e.getActionCommand().equals("111")){
//System.out.println("红色红色");
pan3.setBackground(Color.red);

}else if(e.getActionCommand().equals("222")){
//System.out.println("蓝色蓝色");
pan3.setBackground(Color.BLUE);
}
}
}
class myPanel3 extends JPanel{
public void paint(Graphics g){
super.paint(g);
g.drawString("南海是中国的！", 100, 150);
}
}

class Jtz implements ActionListener{
public void actionPerformed(ActionEvent aa){
if(aa.getActionCommand().equals("111")){
System.out.println("监听者在监听，知道你按下的是红色按钮");

}else {
System.out.println("监听者在监听，知道你按下的是蓝色按钮");

}
}
}

</span>