java

package javatest; import java.awt.*; import javax.swing.JApplet; public class test extends JApplet implements Runnable { private int imageWidth; private int x1, x2; private Image scrollImage, offScreen; public void init() { //取得捲動畫面影像 MediaTracker mediaTracker = new MediaTracker(this); scrollImage = getImage(getDocumentBase(),"scroll.png"); mediaTracker.addImage(scrollImage,0); try { mediaTracker.waitForAll(); } catch(InterruptedException e){ e.printStackTrace(); } offScreen = createImage(getWidth(), getHeight()); imageWidth = scrollImage.getWidth(this); x1 = 0; x2 = -imageWidth; } public void start() { (new Thread(this)).start(); } public void paint(Graphics g) { g.drawImage(offScreen, 0, 0, this); } public void update(Graphics g) { paint(g); } public void run() { Graphics gOffScreen = offScreen.getGraphics(); while(true) { gOffScreen.drawImage(scrollImage, x1, 0, this); gOffScreen.drawImage(scrollImage, x2, 0, this); repaint(); try { Thread.sleep(20); } catch(InterruptedException e){ e.printStackTrace(); } //更新影像位置(產生捲動效果) if(x1 == getWidth()) { x1 = -imageWidth; } else { x1++; } if(x2 == getWidth()) { x2 = -imageWidth; } else { x2++; } } } }