[说明]以下程序实现了在applet里移动图形文件，仔细阅读代码和相关注释，将程序补充完整。[代码6-1] import j ava. awt. *; import j ava.awt.event.*; import java.applet. Applet; public class AppCIU extends Applet implements MouseMotionListener, MouseListener { Image IMG onClick=over(this) title=放大;// 声明 Image 类类型的变量 IMG onClick=over(this) title=放大 int x=70,y=60,posX=70,posY=60,dx,dy; public void init ( ) {IMG onClick=over(this) title=放大=getImage ( getCodeBase ( ) ,"mouse.gif" ); //载入影像addMouseListener ( this );addMouseMotionListener ( this ); } public void mousePressed ( MouseEvent e ) {dx=e.getX()-posX； //取得按下之点与基准点X方向的距离dy=e.getY()-posY； //取得按下之点与基准点Y方向的距离 } public void mouseDragged ( MouseEvent e ) { (1) (2) if ( dx＞0 && dx＜120 && dy＞0 && dy＜60 ) //如果指针落在图形上方{ Graphics g=getGraphics ( ); (3) }} public void paint ( Graphics g ) { (4) (5) (6) } 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 ) {}; }
