j2me简易赛车游戏

 效果图：

MIDlet代码：

package com.javaME.MyRacingGames;

import javax.microedition.lcdui.Display;
import javax.microedition.midlet.MIDlet;
import javax.microedition.midlet.MIDletStateChangeException;

public class HelloRacingGames extends MIDlet {
    private Display dis;


    public HelloRacingGames() {
        // TODO Auto-generated constructor stub
    }

    protected void destroyApp(boolean arg0) throws MIDletStateChangeException {
        // TODO Auto-generated method stub

    }

    protected void pauseApp() {
        // TODO Auto-generated method stub

    }

    protected void startApp() throws MIDletStateChangeException {
        // TODO Auto-generated method stub
        dis = Display.getDisplay(this);
        CarRaceCanvas canvas = new CarRaceCanvas();
        dis.setCurrent(canvas);
    }

}

自定义的GameCanvas代码：

package com.javaME.MyRacingGames;

import java.util.Random;

import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Font;
import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.Image;
import javax.microedition.lcdui.game.GameCanvas;
import javax.microedition.lcdui.game.Sprite;

public class CarRaceCanvas extends GameCanvas implements CommandListener,
        Runnable {
    private Graphics gra;
    // 定义按钮
    private Command cmdStart = new Command("开始", Command.SCREEN, 1);
    private Command cmdPause = new Command("暂停", Command.SCREEN, 1);

    private Sprite myCar;
    private Sprite[] enemy = new Sprite[5];

    private Thread game;
    private boolean loop = true;

    private int road;
    private Random rnd = new Random();
    private int score = 100;
    private Font font = null;

    public CarRaceCanvas() {
        super(true);
        this.prepareResource();
        this.addCommand(cmdStart);
        this.setCommandListener(this);
        gra = this.getGraphics();
        font = Font.getFont(Font.FACE_SYSTEM, Font.STYLE_BOLD, Font.SIZE_LARGE);
    }

    // 初始化资源
    public void prepareResource() {
        try {
            Image myImage = Image.createImage("/myCar.gif");
            myCar = new Sprite(myImage);

            for (int i = 0; i < enemy.length; i++) {
                Image enemyImg = Image.createImage("/enemy.gif");
                enemy[i] = new Sprite(enemyImg);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        for (int i = 0; i < enemy.length; i++) {
            setEnemy(i);
        }

        myCar.setPosition((this.getWidth() - myCar.getWidth()) / 2, (this
                .getHeight() - myCar.getHeight()) / 2);
    }

    public void run() {
        while (loop) {
            drawScreen();
            int state = this.getKeyStates();
            switch (state) {
            case GameCanvas.LEFT_PRESSED:
                myCar.move(-10, 0);
                judgeMyCar();
                break;
            case GameCanvas.UP_PRESSED:
                myCar.move(0, -10);
                judgeMyCar();
                break;
            case GameCanvas.DOWN_PRESSED:
                myCar.move(0, 10);
                judgeMyCar();
                break;
            case GameCanvas.RIGHT_PRESSED:
                myCar.move(10, 0);
                judgeMyCar();
                break;
            }

            try {
                Thread.sleep(50);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    // 判断自己的车是否出界
    public void judgeMyCar() {
        if (myCar.getX() < 0) {
            myCar.setPosition(0, myCar.getY());
        } else if (myCar.getY() > this.getHeight() - myCar.getHeight()) {
            myCar.setPosition(myCar.getX(), this.getHeight()
                    - myCar.getHeight());
        } else if (myCar.getX() > this.getWidth() - myCar.getWidth()) {
            myCar.setPosition(this.getWidth() - myCar.getWidth(), myCar.getY());
        } else if (myCar.getY() < 0) {
            myCar.setPosition(myCar.getX(), 0);
        }
    }
    //设置敌人的位置
    public void setEnemy(int en) {
        int x, y;
        loop: while (true) {
            x = rnd.nextInt((int) this.getWidth() - enemy[en].getWidth());
            y = -rnd.nextInt(this.getWidth() * 10);
            enemy[en].setPosition(x, y);
            //防止敌人车辆重叠
            for (int j = 0; j < enemy.length; j++) {
                if (j != en && enemy[j].collidesWith(enemy[en], true)) {
                    continue loop;
                }
            }
            break;
        }
    }

    // 按钮事件
    public void commandAction(Command cmd, Displayable dis) {
        if (cmd == cmdStart) {
            loop = true;
            game = new Thread(this);
            game.start();
            this.removeCommand(cmdStart);
            this.addCommand(cmdPause);
        } else if (cmd == cmdPause) {
            loop = false;
            game = null;
            this.removeCommand(cmdPause);
            this.addCommand(cmdStart);
        }
    }

    public void drawScreen() {
        gra.setColor(120, 120, 120);
        gra.fillRect(0, 0, this.getWidth(), this.getHeight());

        drawRoad();

        gra.setColor(255, 0, 0);
        gra.setFont(font);

        for (int i = 0; i < enemy.length; i++) {
            enemy[i].move(0, 15);
            enemy[i].paint(gra);
            if (enemy[i].getY() > this.getHeight()) {
                setEnemy(i);
            }
            check(enemy[i]);
        }

        gra.drawString("当前分数：" + score, this.getWidth() / 2, 0, Graphics.TOP
                | Graphics.HCENTER);

        myCar.paint(gra);
        this.flushGraphics();
    }

    public void drawRoad() {
        road += 80;

        gra.setColor(255, 255, 255);
        gra.fillRect((int) this.getWidth() / 2 - 10, road, 20, 150);
        if (road >= this.getHeight()) {
            road = -150;
        }
    }

    // 用于敌人的车辆相互碰撞的检测
    public void checkEnemy(Sprite s) {
        for (int i = 0; i < enemy.length; i++) {
            if (s != enemy[i]) {
                if (s.collidesWith(enemy[i], true)) {
                    if (s.getX() > enemy[i].getX()) {
                        s.move(20, 0);
                        enemy[i].move(-20, 0);
                    } else {
                        s.move(-20, 0);
                        enemy[i].move(20, 0);
                    }
                }
            }
        }
    }

    // 用于自己的车辆和敌方的车辆碰撞检测
    public void check(Sprite en) {
        if (myCar.collidesWith(en, true)) {
            score--;
            if (myCar.getX() > en.getX()) {
                en.move(-20, 0);
                myCar.move(20, 0);
                checkEnemy(en);
            } else {
                en.move(20, 0);
                myCar.move(-20, 0);
                checkEnemy(en);
            }
        }

        if (score == 0) {
            loop = false;
            game = null;

            gra.setColor(120, 120, 120);
            gra.fillRect(0, 0, getWidth(), getHeight());
            gra.setColor(255, 0, 0);
            gra.setFont(font);
            gra.drawString("您输了", this.getWidth() / 2, 20, Graphics.TOP
                    | Graphics.HCENTER);
            this.removeCommand(cmdPause);
            this.removeCommand(cmdStart);
        }
    }
}