gamectrl.java

J2ME手机游戏一个赛车躲避障碍的小实例

/*
 * 创建日期 2005-6-23
 *
 * TODO 要更改此生成的文件的模板，请转至
 * 窗口 － 首选项 － Java － 代码样式 － 代码模板
 */
package game;


import java.util.Timer;

import javax.microedition.lcdui.Alert;
import javax.microedition.lcdui.AlertType;
import javax.microedition.lcdui.Canvas;
import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.Image;
import javax.microedition.midlet.MIDletStateChangeException;

/**
 * @author Administrator
 *
 * TODO 要更改此生成的类型注释的模板，请转至
 * 窗口 － 首选项 － Java － 代码样式 － 代码模板
 */
public class GameCtrl extends Canvas implements CommandListener{
	private final Command startCommand;
	private final Command quitCommand;
	private final RacingMIDlet midlet;
	private Graphics graph;
	private Timer timer = new Timer();
	private NextFrame nextFrame;
	
	// 炸弹图象
	public Image bombImage;
	
	// 赛车图象
	public Image carImage;
	
	// 屏幕尺寸
	public int width = 0;
	public int height = 0;
	
	// 公路中线模式
	public boolean lineMode = true;
	
	// 赛车水平位置
	public int carPos = 0;
	
	// 炸弹位置
	public int[] bombPosX = {0, 0, 0, 0};
	public int[] bombPosY = {0, 0, 0, 0};
	
	// 炸弹是否出界
	public boolean[] bombCanUse = {false, false, false, false};
	
	// 游戏结束标志
	public boolean isGameOver = false;
	
	// 游戏开始标志
	public boolean isGameRun = false;
	
	// 游戏积分
	public int score = 0;

	/**
	 * 
	 */
	public GameCtrl(RacingMIDlet midlet) {
		super();
		
		// 保存MIDlet类对象
		this.midlet = midlet;

		// 得到屏幕尺寸
		width = getWidth();
		height = getHeight();

		try	{
			// 装载炸弹图象
			bombImage = Image.createImage("/bomb.png");
			
			// 装载赛车图象
			carImage = Image.createImage("/car.png");
		}catch(Exception e)	{}

		// 添加命令按键
		quitCommand = new Command("退出", Command.EXIT, 2);
		addCommand(quitCommand);
		
		startCommand = new Command("开始", Command.OK, 1);
		addCommand(startCommand);

		// 侦听按键响应
		setCommandListener(this);		
	}
	
	/* （非 Javadoc）
	 * @see javax.microedition.lcdui.Displayable#paint(javax.microedition.lcdui.Graphics)
	 */
	protected void paint(Graphics g) {
		graph = g;
		if (isGameOver == true && isGameRun == true){
			isGameRun = false;
			
			// 显示logo
			Alert result = new Alert("本局积分", String.valueOf(score), null, AlertType.INFO);
				
			// 延迟4秒 
			result.setTimeout(2000);

			// 显示闪屏界面
			midlet.display.setCurrent(result, this);			
			return;
		}

		if (isGameRun == true){
			// 白色清空画布 
			graph.setColor(255, 255, 255);
			graph.fillRect(0, 0, width, height);
				
			// 绘制动态公路中线
			g.setColor(0, 0, 255);
			if (lineMode == true){
				lineMode = false;
				for (int i = 0; i < height; i += 20)
					g.drawLine(width / 2, i, width / 2, i + 10);
			}else{
				lineMode = true;
				for (int i = 10; i < height; i += 20)
					g.drawLine(width / 2, i, width / 2, i + 10);
			}
			
			// 绘制赛车
			g.drawImage(carImage, carPos, height - carImage.getHeight(), Graphics.HCENTER | Graphics.VCENTER);	
			
			// 绘制炸弹
			for (int i = 0; i < 4; i++){
				if (bombCanUse[i] == true)
					g.drawImage(bombImage, bombPosX[i], bombPosY[i], Graphics.HCENTER | Graphics.VCENTER);
			}
		}
	}
	
	/* （非 Javadoc）
	 * @see javax.microedition.lcdui.CommandListener#commandAction(javax.microedition.lcdui.Command, javax.microedition.lcdui.Displayable)
	 */
	public void commandAction(Command arg0, Displayable arg1) {
		if (arg0 == startCommand){
			// 用户开始游戏
			initialize();
		}
		
		if (arg0 == quitCommand){
			if (isGameRun == true){
				// 结束游戏
				isGameOver = true;
				isGameRun = false;
			
				// 关闭定时器
				nextFrame.cancel();
			}

			// 用户退出游戏
			try{
				midlet.quit();
			}
			catch(MIDletStateChangeException e){}
		}
	}
	
	private void initialize() {
		// 初始化数据	
		carPos = width * 3 / 4;
		score = 0;
		for (int i = 0; i < 4; i++){
			bombPosX[i] = 0;
			bombPosY[i] = 0;
			bombCanUse[i] = false;
		}

		// 白色清空画布 
		graph.setColor(255, 255, 255);
		graph.fillRect(0, 0, width, height);

		// 开启定时器
		nextFrame = new NextFrame(this);
		timer.schedule(nextFrame, 300, 300);		

		// 重绘屏幕
		isGameOver = false;
		isGameRun = true;
		repaint();				
	}

	protected void keyPressed(int keyCode) {
		// 游戏结束后不处理按键
		if (isGameOver == true)
			return;
			
		// 得到按键动作
		int gameAction = getGameAction(keyCode);
		switch (gameAction) {
		case RIGHT:
			// 右移赛车
			carPos += 5;
			
			// 防止越界
			if (carPos > width - carImage.getWidth() / 2)
				carPos = width - carImage.getWidth() / 2;
			break;

		case LEFT:	
			// 左移赛车
			carPos -= 5;

			// 防止越界
			if (carPos < carImage.getWidth() / 2)
				carPos = carImage.getWidth() / 2;
			break;

		default:    
			break;
		}

		// 重绘屏幕
		repaint();
	}

}