线程控制动画

<script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"> </script> 线程是程序的一部分，是系统调度的基本单位。线程是控制动画的理想选择。将动画的工作放在线程上，可以释放出程序的其他部分来处理别的任务。 线程的现实是通过java.lang中的Thread类，要使某一个类能使用线程，必须实现Runnable接口，该接口包含了唯一一个方法run()。run()方法是线程类的核心，--------动画程序中产生运动。通过调用线程的start ()方法，致使run()方法被调用。下边这个程序描绘了一个运动中的圆。 import java.awt.*; import java.awt.event.*; import javax.swing.*; public class Cartoon extends JApplet implements Runnable { Graphics screenBuffer = null;//创建图形缓冲区 Image screenImage = null; private Thread runner; private int x = 5; private int move = 1; public void init ( ) { screenImage = createImage ( 230, 160 ); screenBuffer = screenImage.getGraphics ( ); } public void start ( ) { if (runner == null) { runner = new Thread( this ); runner.start(); } } public void run( ) { Thread circle = Thread.currentThread ( ); while ( runner == circle )//指向同一对象，便开始运行 { x = move; if ( ( x > 105 ) || ( x < 5 )) move *= -1; repaint ( ); } } public void drawCircle( Graphics gc ) { Graphics2D g2D = ( Graphics2D ) gc; g2D.setColor ( Color.blue ); g2D.fillRect ( 0, 0, 100, 100 ); g2D.setColor ( Color.yellow ); g2D.fillRect ( 100, 0, 100, 100 ); g2D.setColor ( Color.red ); g2D.fillOval ( x, 5, 90, 90 ); } public void paint( Graphics g ) { screenBuffer.setColor ( Color.white ); screenBuffer.fillRect (0,0,96,60); drawCircle ( screenBuffer ); //将缓冲区的图像复制到主缓冲区中 g.drawImage ( screenImage, 130, 100, this ); } }