package cn.sxt.game;
import java.awt.Color;
import java.awt.Font;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.util.Date;
/**
* 飞机游戏的主窗口
* @author 高淇
*
*/
public class MyGameFrame extends Frame {
Image planeImg = GameUtil.getImage("images/plane.png");
Image bg = GameUtil.getImage("images/bg.jpg");
Plane plane = new Plane(planeImg,250,250);
Shell[] shells = new Shell[50];
Explode bao ;
Date startTime = new Date();
Date endTime;
int period; //游戏持续的时间
@Override
public void paint(Graphics g) { //自动被调用。 g相当于一只画笔
Color c = g.getColor();
g.drawImage(bg, 0, 0, null);
plane.drawSelf(g); //画飞机
//画出所有的炮弹
for(int i=0;i<shells.length;i++){
shells[i].draw(g);
//飞机和炮弹的碰撞检测!!!
boolean peng = shells[i].getRect().intersects(plane.getRect());
if(peng){
plane.live = false;
if(bao ==null){
bao = new Explode(plane.x, plane.y);
endTime = new Date();
period = (int)((endTime.getTime()-startTime.getTime())/1000);
}
bao.draw(g);
}
//计时功能,给出提示
if(!plane.live){
g.setColor(Color.red);
Font f = new Font("宋体", Font.BOLD, 50);
g.setFont(f);
g.drawString("时间:"+period+"秒", (int)plane.x, (int)plane.y);
}
}
g.setColor(c);
}
//帮助我们反复的重画窗口!
class PaintThread extends Thread {
@Override
public void run() {
while(true){
repaint(); //重画
try {
Thread.sleep(40); //1s=1000ms
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
//定义键盘监听的内部类
class KeyMonitor extends KeyAdapter {
@Override
public void keyPressed(KeyEvent e) {
plane.addDirection(e);
}
@Override
public void keyReleased(KeyEvent e) {
plane.minusDirection(e);
}
}
/**
* 初始化窗口
*/
public void launchFrame(){
this.setTitle("尚学堂学员_程序猿作品");
this.setVisible(true);
this.setSize(Constant.GAME_WIDTH , Constant.GAME_HEIGHT);
this.setLocation(300, 300);
this.addWindowListener(new WindowAdapter() {
@Override
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
new PaintThread().start(); //启动重画窗口的线程
addKeyListener(new KeyMonitor()); //给窗口增加键盘的监听
//初始化50个炮弹
for(int i=0;i<shells.length;i++){
shells[i] = new Shell();
}
}
public static void main(String[] args) {
MyGameFrame f = new MyGameFrame();
f.launchFrame();
}
private Image offScreenImage = null;
public void update(Graphics g) {
if(offScreenImage == null)
offScreenImage = this.createImage(Constant.GAME_WIDTH,Constant.GAME_HEIGHT);//这是游戏窗口的宽度和高度
Graphics gOff = offScreenImage.getGraphics();
paint(gOff);
g.drawImage(offScreenImage, 0, 0, null);
}
}
老师,我这个照着敲得代码,为什么运行有时候会出现如下异常?

