【Java开源代码栏目提醒】:网学会员鉴于大家对Java开源代码十分关注,论文会员在此为大家搜集整理了“walker.java”一文,供大家参考学习
/**
* Title:
Java语言多媒体编程演示
* Description: Java语言多媒体编程
演示,用于北京师范大学计算机系Java
课程教学示范。
* Copyright: Copyright (c) 2001
* Company: 北京师范大学
计算机系
* @author 孙一林
* @version 1.0
*/
import java.awt.MediaTracker;
import java.awt.Graphics;
import java.awt.Image;
//import java.applet.AudioClip;
public class Walker extends java.applet.Applet implements Runnable{
Image offScreenImg; //存放备用屏幕的内容
Graphics offScreenG; //备用屏幕的绘图环境
MediaTracker tracker; //媒体跟踪器
Image walkerImgs[]=new Image[5]; //存放鸵鸟走路姿势图像
Image currentImg; //当前放映的鸵鸟动作图像
int xpos,ypos=0; //鸵鸟动作图像显示的位置
int walk_step=20; //鸵鸟图像每次移动的距离
int delay = 250; //每帧时延(毫秒)
Thread runThread;
Image bgImage; //存放草原背景图像
int applet_width,applet_height;
int birdImg_width; //鸵鸟图像宽度
//AudioClip bgmusic;
public void init(){
tracker = new MediaTracker(this);
for (int i=0;i<walkerImgs.length;i++){ //获取鸵鸟动作图像
walkerImgs[i]=getImage(getCodeBase(),"images/bird"+i+".gif");
tracker.addImage(walkerImgs[i], 0); //列入0组跟踪范围
}
bgImage = getImage(getCodeBase(),"images/"+"bg.gif"); //获取草原背景图像
tracker.addImage(bgImage, 0); //列入0组跟踪范围
//bgmusic=getAudioClip(getDocumentBase(),"space.au"); //获取背景音乐
applet_width=size().width;
applet_height=size().height;
try {
offScreenImg = createImage (applet_width,applet_height);//创建备用屏幕
offScreenG = offScreenImg.getGraphics ();//获取备用屏幕的绘图环境
}
catch (Exception e) {
offScreenG = null; //若出错,就置备用屏幕的绘图上下文环境为null
}
}
/*
public boolean mouseMove(java.awt.Event evt, int x, int y) {
ypos = y; // 获取鼠标Y方向的值
return true;
}
*/
public void start (){
if (runThread==null){
runThread=new Thread(this);
runThread.start();
}
}
public void stop(){
if (runThread!=null){
//if(bgmusic!=null)
// bgmusic.stop();
runThread.stop();
runThread=null;
}
}
public void run(){
try{
tracker.waitForID(0); //等待0组中所有图像的到达
}catch(InterruptedException e){
return;
}
//if(bgmusic!=null)
// bgmusic.loop();
birdImg_width=walkerImgs[0].getWidth(this);
int i=0;
while(true){
for(xpos=-birdImg_width;xpos<=applet_width;xpos+=walk_step){//计算位置
currentImg=walkerImgs[i];
repaint();
i=(i+1)%walkerImgs.length; //计算下一帧是哪幅图像
try{Thread.sleep(delay);}
catch(InterruptedException e){}
}
}
}
public void paint(Graphics g){
g.drawImage(bgImage,0,0,this);
g.drawImage(currentImg,xpos,ypos,this);
}
public void update(Graphics g){
if (offScreenG!=null) { //如果备用屏幕创建成功
paint(offScreenG);
g.drawImage(offScreenImg,0,0,this); //将备用屏幕内容画到当前屏幕来
}
else
paint(g);
}
}