Java的几种事件监听步骤

Java的几种事件监听方法

这几天在看Java的图形界面编程，由于上课也没书，几乎没学什么，于是想自己做个堆积木来好好学一下。写完之后，被监听弄得出了好几个问题，幸好学长帮我的忙才对Java的事件驱动模型有了个基本的了解，看来用Java做GUI真的不是件蛮爽的事。后来自己好好总结了一下，想清了下面四种常用的监听方法：

import javax.swing.*;
import java.awt.event.*;


//The first method
//该方法有缺陷，如果本类要继承于另外一个类，那么由于java的单继承机制，该类就不能再继承于适配器类
//使用该方法时需要注意适配器类中的方法名字要写正确，否则jdk会认为是新增的方法而不会报错
public class JFrameDemo extends WindowAdapter 
{
    JFrame jfr;
    public JFrameDemo(String name)
    {
        jfr = new JFrame(name);
        jfr.setSize(200,100);
        jfr.setVisible(true);
        jfr.addWindowListener(this);
    }

    public void windowClosing(WindowEvent e)
    {
        System.exit(0);
    }

    public static void main(String[] args)
    {
        new JFrameDemo("jframedemo");
    }
}



//The second method
public class JFrameDemo extends JFrame
{
    public JFrameDemo(String name)
    {
        super(name);
        setSize(200,100);
        setVisible(true);
        addWindowListener(new WindowOP());
    }

    public static void main(String[] args)
    {
        new JFrameDemo("jramedemo");
    }
}

class WindowOP implements WindowListener
{
    public void windowClosed(WindowEvent e)            {}
    public void windowActivated(WindowEvent e)        {}
    public void windowClosing(WindowEvent e) 
    {        
        System.exit(0);
    }
    public void windowDeactivated(WindowEvent e)    {}
    public void windowDeiconified(WindowEvent e)    {}
    public void windowIconified(WindowEvent e)        {}
    public void windowOpened(WindowEvent e)            {}

}




//The third method
//通常而言，这种方法是较好的
//将实现接口WindowListener的部份放在class JFrameDemo中，这样就只用一个类
//这时在构造方法中添加监听的对象就是this本身了，也就是addWindowListener(this);
public class JFrameDemo extends JFrame implements WindowListener
{
    public JFrameDemo(String name)
    {
        super(name);
        setSize(200,100);
        setVisible(true);
        addWindowListener(this);
    }

    public void windowClosed(WindowEvent e)            {}
    public void windowActivated(WindowEvent e)        {}
    public void windowClosing(WindowEvent e) 
    {        
        System.exit(0);
    }
    public void windowDeactivated(WindowEvent e)    {}
    public void windowDeiconified(WindowEvent e)    {}
    public void windowIconified(WindowEvent e)        {}
    public void windowOpened(WindowEvent e)            {}
}




//The forth method
//采用内部类的方法来实现WindowListener接口，即
addWindowListener(new WindowListener()
{
    public void windowCloing(WindowEvent e) {}
    public void windowActivated(WindowEvent e) {}
    public void windowClosing(WindowEvent e) 
    {        
        System.exit(0);
    }
    public void windowDeactivated(WindowEvent e) {}
    public void windowDeiconified(WindowEvent e) {}
    public void windowIconified(WindowEvent e)  {}
    public void windowOpened(WindowEvent e)  {}
});
//但这种方法通常只能用于较小的程序中