经常看到许多学习手机游戏开发,对于线程一直不知道该如何控制,下面是我写的一个例子,希望对开发游戏的兄弟有所帮助,有何不妥之处也请指正!


GameMIDlet.java

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


public class GameMIDlet extends MIDlet {
Game game;
Display display;


public GameMIDlet() {
game = new Game(this);
display = Display.getDisplay(this);
}

protected void startApp() throws MIDletStateChangeException {
game.setGameState(game.LOGO, 30);
game.start();
display.setCurrent(game);
}

protected void pauseApp() {
notifyPaused();
}

protected void destroyApp(boolean _boolean) throws MIDletStateChangeException {
notifyDestroyed();
}
}

Game.java

import javax.microedition.lcdui.*;
import com.nokia.mid.ui.*;

/**
* <p>Title: </p>
*
* <p>Description: </p>
*
* <p>Copyright: Copyright (c) 2005</p>
*
* <p>Company: </p>
*
* @author not attributable
* @version 1.0
*/
public class Game extends FullCanvas implements Runnable ,CommandListener{

private GameMIDlet gameMIDlet;

private boolean runGame;//游戏是否启动
private int fps;//频率
private int gameState = -1; //当前游戏状态
/**
* 游戏状态参数
*/

public final byte LOGO = 0;
public final byte MENU = 1;
public final byte ABOUT = 2;
public final byte HELP = 3;
public final byte WAIT = 4;
public final byte LOGINFORM = 5;
public final byte RESULT = 6;
public final byte LOADING = 7;
public final byte REGIST = 8;
public final byte GAME = 9;


private Image bufferedImage;//双缓冲图片


private Form form;
private Command cmdReg, cmdBack; // 注册、登陆、返回、修改按钮对象
private TextField tfAccount, tfPassWord; // 昵称、密码，TextField对象
/**
* 默认构造方法
*/
public Game(GameMIDlet midlet) {
gameMIDlet = midlet;
int width = 128;
int height = 128;

// create image buffer:
bufferedImage = Image.createImage(width, height);
}


protected void keyPressed(int keyCode) {
if (keyCode == -5) {
setGameState(LOGINFORM, 30);
}
}

/**
*设置当前状态
* @param bGameState byte 状态值
* @param newFPS byte 当前状态下的频率
*/

public void setGameState(int bGameState,int newFPS){
this.release();
this.gameState = bGameState;
this.fps = newFPS;
this.init();
}
/**
* 设置当前状态
* @param bGameState int 状态值
*/
public void setGameState(int bGameState){
this.release();
this.gameState = bGameState;
this.fps = 30;
this.init();
}
/**
* 得到当前状态
* @return int
*/
public int getGameState(){
return this.gameState;
}

/**
* 游戏主线程启动
*/

public void start() {
runGame = true;
Thread t = new Thread(this);
t.start();
}

/**
* 游戏主线程停止
*/
public void stop() {
runGame = false;
}
/**
* 实现Runnable接口
*/
public void run() {
Graphics g = bufferedImage.getGraphics();//得到Graphics绘图对象
long startTime;
int interval = 1000 / this.fps;
byte count = 2;//垃圾回收次数控制
byte n = count;
Thread currentThread = Thread.currentThread();
while (runGame && currentThread == Thread.currentThread()) {
interval = 1000 / this.fps;
startTime = System.currentTimeMillis();

this.input();

this.work();

drawScreen(g);
if (gameState != LOGINFORM) {
repaint();//请求刷新屏幕
serviceRepaints();
}

waitSomething(startTime, interval);
if (n == 0) {
Runtime.getRuntime().gc();
n = count;
}
n--;
}
}
/**
* 线程休眠一段时间
* @param loopStartTime long
* @param interval long
*/
protected void waitSomething(long loopStartTime, long interval) {
long time = System.currentTimeMillis() - loopStartTime;
if (time < interval) {
try {
Thread.sleep(interval - time);
} catch (InterruptedException e) {}
} else {
Thread.yield();
}
}

public void paint(Graphics g) {
g.drawImage(this.bufferedImage, 0, 0, Graphics.TOP | Graphics.LEFT);
}
/**
* 当前状态初始化
*/
protected void init() {
switch (getGameState()) {
case LOGINFORM:
initLoginForm();
break;
default:
break;
}
}


/**
* 当前状态释放资源
*/
protected void release() {
switch (getGameState()) {
case LOGINFORM:
releaseLoginForm();
break;
default:
break;
}
Runtime.getRuntime().gc();
}
/**
* 当前状态下的用户输入
*/
protected void input() {
}
/**
* 当前状态下的逻辑处理
*/
protected void work() {
}
/**
* 当前状态下的绘制
* @param g Graphics
*/
protected void drawScreen(Graphics g) {
switch (getGameState()) {
case LOG
g.drawString("aaa",10,50,0);
break;
default:
break;
}
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