flamesign.java

Java案例开发集锦,里面提供了很好的学习例子

import java.applet.Applet;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.MediaTracker;

public class FlameSign extends Applet implements Runnable
//在applet中支持线程，需要实现Runnable接口
{
	private Image bimg, fimg,offI, virtualI;

	private Graphics offG, virtualG;

	private Thread thread = null;

	private MediaTracker imageTracker;

	private int height, width, X, Y;

	public void init() {
		//初始化applet,加载背景图片、前景图片
		String imageName = getParameter("Image1");
		String imageName2 = getParameter("Image2");
		bimg = getImage(getDocumentBase(), imageName);//获取背景图片
		fimg = getImage(getDocumentBase(), imageName2);//获取前景图片
		imageTracker = new MediaTracker(this); //创建一个媒体跟踪器的实例
//		将图片加入到 MedialTracker 的监视队列中去， image 为要被监视的图像对象， 
		//0 为监视图像在监视队列中的标识号 
		imageTracker.addImage(bimg, 0); 
		imageTracker.addImage(fimg, 0);

		width = this.getSize().width; //设置applet宽度
		height = this.getSize().height; //设置applet高度
		try {
			imageTracker.waitForID(0); //加载图片
		} catch (InterruptedException e) {
		}

		offI = createImage(width, height);
		offG = offI.getGraphics();
		virtualI = createImage(width * 2, height * 2);
		virtualG = virtualI.getGraphics();
	}

	public void start() {
		//启动applet,创建并启动一个线程
		if (thread == null) {
			thread = new Thread(this); //以applet初始化线程
			thread.start(); //启动线程，调用run()方法
		}
	}

	public void run() {
		//线程调用开始
		int x = 0, y = 0;
		int tileWidth = bimg.getWidth(this); //设置招牌宽度
		int tileHeight = bimg.getHeight(this); //设置招牌高度
		while (thread != null) {
			try {
				Thread.sleep(10);
				x = virtualI.getWidth(this) - width;
				y = virtualI.getHeight(this) - height;
				//在不同的坐标位置输出图像以产生燃烧效果
				for (; (x > 0) && (y > 0); x--, y--) {
					if ((x == 0) || (y == 0)) {
						x = virtualI.getWidth(this) - width;
						y = virtualI.getHeight(this) - height;
					}

					//输出图像，产生燃烧特效
					for (int j = 0; j < virtualI.getHeight(this); j = j
							+ tileHeight)
						for (int i = 0; i < virtualI.getWidth(this); i = i
								+ tileWidth)
							virtualG.drawImage(bimg, i, j, this);

					virtualG.drawImage(fimg, x, y, width, height, this);
					offG.drawImage(virtualI, -x, -y, this);

					//输出applet，调用update()方法
					repaint();
				}
			} catch (InterruptedException e) {
			}
		}
	}

	public void update(Graphics g) {
		//调用paint()方法
		paint(g);
	}

	public void paint(Graphics g) {
		//输出applet
		g.drawImage(offI, 0, 0, this);
	}
}