10+

本压缩文档为《Java大学实用教程》（7-121-00959-5 电子工业出版社 2005.3） 的电子教案。

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
class Win extends JFrame implements MouseMotionListener,MouseListener 
{  
    JButton button[]=new JButton[6];
    JTextField text;
    JLayeredPane layerPane;
    Container con; 
    Win()
    { 
      layerPane=new JLayeredPane();
      layerPane.setLayout(new FlowLayout());
      con=getContentPane();
      con.add(layerPane,BorderLayout.CENTER);
      for(int i=0;i<button.length;i++)
         {
           button[i]=new JButton("用鼠标拖动我"+i);
           button[i].addMouseMotionListener(this);
           button[i].addMouseListener(this);
           layerPane.add(button[i],JLayeredPane.DEFAULT_LAYER);
         } 
      con.addMouseMotionListener(this);
      setBounds(10,10,300,300);
      setVisible(true); 
      validate();
      setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
    public void mouseMoved(MouseEvent e){} 
    public void mouseDragged(MouseEvent e)
    { 
       JComponent source=(JComponent)e.getSource(); 
       layerPane.setLayer(source,JLayeredPane.DRAG_LAYER);
       int x=e.getX();
       int y=e.getY();
       java.awt.Point point=SwingUtilities.convertPoint(source,x,y,con);
       int x1=(int)point.getX();         //获取鼠标指针在容器坐标系中的坐标。
       int y1=(int)point.getY();
       int w=source.getSize().width;
       int h=source.getSize().height;
       source.setLocation(x1-w/2,y1-h/2); //组件中心跟随鼠标指针移动。
    }
    public void mouseReleased(MouseEvent e)
    {
       JComponent source=(JComponent)e.getSource(); 
       layerPane.setLayer(source,JLayeredPane.DEFAULT_LAYER);
    }
    public void mousePressed(MouseEvent e){}
    public void mouseEntered(MouseEvent e){}
    public void mouseExited(MouseEvent e){}
    public void mouseClicked(MouseEvent e){}
}
public class Example
{  public static void main(String args[])
    { 
       Win win=new Win();
    }
}