100分！求有关动画的程序代码。分不够另帖再加。

http://bbs.nju.edu.cn/vd418023/bbsanc?path=/groups/GROUP_3/Java/Java3D/M.925202603.A
不知道你能不能访问

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.util.*;
import javax.swing.*;/**
   Shows an animated bouncing ball.
*/
public class Bounce
{
   public static void main(String[] args)
   {
      JFrame frame = new BounceFrame();
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.show();
   }
}/**
   The frame with canvas and buttons.
*/
class BounceFrame extends JFrame
{
   /**
      Constructs the frame with the canvas for showing the
      bouncing ball and Start and Close buttons
   */
   public BounceFrame()
   {
      setSize(WIDTH, HEIGHT);
      setTitle("Bounce");      Container contentPane = getContentPane();
      canvas = new BallCanvas();
      contentPane.add(canvas, BorderLayout.CENTER);
      JPanel buttonPanel = new JPanel();
      addButton(buttonPanel, "Start",
         new ActionListener()
            {
               public void actionPerformed(ActionEvent evt)
               {
                  addBall();
               }
            });      addButton(buttonPanel, "Close",
         new ActionListener()
            {
               public void actionPerformed(ActionEvent evt)
               {
                  System.exit(0);
               }
            });
      contentPane.add(buttonPanel, BorderLayout.SOUTH);
   }   /**
      Adds a button to a container.
      @param c the container
      @param title the button title
      @param listener the action listener for the button
   */
   public void addButton(Container c, String title,
      ActionListener listener)
   {
      JButton button = new JButton(title);
      c.add(button);
      button.addActionListener(listener);
   }   /**
      Adds a bouncing ball to the canvas and makes
      it bounce 1,000 times.
   */
   public void addBall()
   {
      try
      {
         Ball b = new Ball(canvas);
         canvas.add(b);         for (int i = 1; i <= 1000; i++)
         {
            b.move();
            Thread.sleep(5);
         }
      }
      catch (InterruptedException exception)
      {
      }
   }   private BallCanvas canvas;
   public static final int WIDTH = 450;
   public static final int HEIGHT = 350;
}/**
   The canvas that draws the balls.
*/
class BallCanvas extends JPanel
{
   /**
      Add a ball to the canvas.
      @param b the ball to add
   */
   public void add(Ball b)
   {
      balls.add(b);
   }   public void paintComponent(Graphics g)
   {
      super.paintComponent(g);
      Graphics2D g2 = (Graphics2D)g;
      for (int i = 0; i < balls.size(); i++)
      {
         Ball b = (Ball)balls.get(i);
         b.draw(g2);
      }
   }   private ArrayList balls = new ArrayList();
}/**
   A ball that moves and bounces off the edges of a
   component
*/
class Ball
{
   /**
      Constructs a ball in the upper left corner
      @c the component in which the ball bounces
   */
   public Ball(Component c) { canvas = c; }   /**
      Draws the ball at its current position
      @param g2 the graphics context
   */
   public void draw(Graphics2D g2)
   {
      g2.fill(new Ellipse2D.Double(x, y, XSIZE, YSIZE));
   }   /**
      Moves the ball to the next position, reversing direction
      if it hits one of the edges
   */
   public void move()
   {
      x += dx;
      y += dy;
      if (x < 0)
      {
         x = 0;
         dx = -dx;
      }
      if (x + XSIZE >= canvas.getWidth())
      {
         x = canvas.getWidth() - XSIZE;
         dx = -dx;
      }
      if (y < 0)
      {
         y = 0;
         dy = -dy;
      }
      if (y + YSIZE >= canvas.getHeight())
      {
         y = canvas.getHeight() - YSIZE;
         dy = -dy;
      }      canvas.paint(canvas.getGraphics());
   }   private Component canvas;
   private static final int XSIZE = 15;
   private static final int YSIZE = 15;
   private int x = 0;
   private int y = 0;
   private int dx = 2;
   private int dy = 2;
}

请问，Graphics 和Ｇraphics 2D的区别是什么？Graphics2D 是　Graphics 的一个扩充吗？我的意思是，Graphics2D 继承自Graphics ，再在其基础上扩展。
如何初始化一个Ｇraphics?

这是个Applet
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.awt.geom.*;public class HorseTest extends JApplet implements ActionListener
{
private JButton btnStart,btnPause;
private JPanel buttonPanel;
private int xGreen=20,yGreen=20,xBlue=60,yBlue=20,xRed=100,yRed=20,count=2;
private Container c;
private Timer t;

public void init()
{
c=getContentPane();
t=new Timer(50,this);

buttonPanel=new JPanel();
buttonPanel.setBackground(Color.magenta);
btnStart=new JButton("开始");
btnStart.addActionListener(this); btnPause=new JButton("暂停");
btnPause.addActionListener(this); buttonPanel.add(btnStart);
buttonPanel.add(btnPause);
c.add(buttonPanel,BorderLayout.SOUTH);
}
public void actionPerformed(ActionEvent e)
{
if(e.getSource()==btnPause)
t.stop();
else if(e.getSource()==btnStart)
t.start();
     else
{
if(xRed>=20 && xRed<340 && yRed==20)         //第一转向
xRed+=40;
else if(xRed==340 && yRed>=20 && yRed<340)   //第二
yRed+=40;
else if(yRed>=340 && xRed<=340 && xRed>20)   //第三
      xRed-=40;
else if( xRed==20 && yRed>20 && yRed<=340 )  //第四
yRed-=40;

if(xBlue>=20 && xBlue<340 && yBlue==20)
xBlue+=40;
else if(xBlue==340 && yBlue>=20 && yBlue<340)
yBlue+=40;
else if(yBlue>=340 && xBlue<=340 && xBlue>20)
      xBlue-=40;
else if(yBlue>20 && yBlue<=340 && xBlue==20 )
yBlue-=40; if(xGreen>=20 && xGreen<340 && yGreen==20)
xGreen+=40;
else if(xGreen==340 && yGreen>=20 && yGreen<340)
yGreen+=40;
else if(yGreen>=340 && xGreen<=340 && xGreen>20)
      xGreen-=40;
else if(yGreen>20 && yGreen<=340 && xGreen==20 )
yGreen-=40;
}

              repaint();
}
public void paint(Graphics g)
{
super.paint(g);
Graphics2D g2=(Graphics2D)g; g2.setColor(Color.magenta);
g2.drawRect(20,20,360,360);
g2.setColor(Color.yellow);
g2.drawRect(60,60,280,280); count++;
if(count%3==0)
  g2.setColor(Color.blue);
else if(count%3==1)
  g2.setColor(Color.green);
else if(count%3==2)
  g2.setColor(Color.red);
g2.fill(new Ellipse2D.Double(xGreen,yGreen,40,40));

if(count%3==0)
  g2.setColor(Color.green);
else if(count%3==1)
  g2.setColor(Color.red);
else if(count%3==2)
  g2.setColor(Color.blue);
g2.fill(new Ellipse2D.Double(xBlue,yBlue,40,40));

if(count%3==0)
  g2.setColor(Color.red);
else if(count%3==1)
  g2.setColor(Color.blue);
else if(count%3==2)
  g2.setColor(Color.green);
g2.fill(new Ellipse2D.Double(xRed,yRed,40,40));
}
}

中文电子版教程
Java 2 图形设计卷Ⅰ：AWT
http://ecapital.myetang.com/java/tutorial/awt01/index.htmlJava 2 图形设计卷Ⅱ：SWING
http://ecapital.myetang.com/swing/tutorial/s02/index.html里面专门讲了几章动画

调试易

100分！求有关动画的程序代码。分不够另帖再加。

解决方案 »