【说明】 以下程序实现了利用鼠标任意移动该圆形的位置，仔细阅读代码和相关注释，将程序补充完整。 【代码6】 import java.awt.*; import java.awt.event.*; public class CIUSAMPLE extends Frame implements MouseMotionListener, MouseListener { static CIUSAMPLE frm=new CIUSAMPLE (); int x=70,y=60,posX=70,posY=60,dx,dy; public static void main ( String args[]) { frm.setTitle ("Dragging a circle"); frm.setSize ( 200,150 ); (1) frm.addMouseMotionListener ( frm ); frm. setVisible ( true ); } public void mousePressed ( MouseEvent e ) { (2) dy=e.getY () -posY; } public void mouseDragged ( MouseEvent e ) { (3) y=e.getY () -dy;if ( dx＞0 && dx＜50 && dy＞0 && dy＜50 ) //如果指我落在正方形区域内{ Graphics g=getGraphics (); (4) } } public void paint ( Graphics g ) { g.setColor ( Color. pink ); // 设置绘图颜色为粉红 g.fillOval ( x,y,50,50 ); //以基准点为图形的左上角绘出圆形 (5) posY=y; } public void mouseMoved ( MouseEvent e ) { } public void mouseReleased ( MouseEvent e ) { } public void mouseEntered ( MouseEvent e ) { } public void mouseExited ( MouseEvent e ) { } public void mouseClicked ( MouseEvent e ) { } }