Java 2使用教程：事件的处理

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


class LP extends JLayeredPane implements MouseListener,MouseMotionListener
{
JButton button;
int x,y,a,b,x0,y0;
LP(){
button=new JButton("用鼠标拖动我");
button.addMouseListener(this);
button.addMouseMotionListener(this);
setLayout(new FlowLayout());
add(button,JLayeredPane.DEFAULT_LAYER);
}
public void mousePressed(MouseEvent e){
JComponent com = null;
com = (JComponent)e.getSource();
setLayer(com,JLayeredPane.DRAG_LAYER);
a = com.getBounds().x;
b = com.getBounds().y;
x0 = e.getX();
y0 = e.getY();
}
public void mouseReleased(MouseEvent e){
JComponent com=null;
com = (JComponent)e.getSource();
setLayer(com,JLayeredPane.DEFAULT_LAYER);
}
public void mouseEntered(MouseEvent e){}
public void mouseExited(MouseEvent e){}
public void mouseClicked(MouseEvent e){}
public void mouseMoved(MouseEvent e){}
public void mouseDragged(MouseEvent e){
Component com = null;
if(e.getSource() instanceof Component){
com = (Component)e.getSource();
a = com.getBounds().x;
b = com.getBounds().y;
x = e.getX();
y = e.getY();
a = a+x;
b = b+y;
com.setLocation(a-x0,b-y0);
}
}
}


class WindowMove extends JFrame
{
LP layeredPane;
WindowMove(){
layeredPane = new LP();
add(layeredPane,BorderLayout.CENTER);
setVisible(true);
setBounds(12,12,300,300);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}


public class E
{
public static void main(String args[]){
WindowMove win = new WindowMove();
win.setTitle("处理鼠标拖动事件");
win.setBounds(10,10,460,360);
}
}