游戏结构

MIDlet

public class GameMidlet
extends MIDlet
{
private PlayCanvas play;

public static GameMidletinstance;

public GameMidlet()
{

instance = this;
play=new PlayCanvas(this);
}

protected void pauseApp()
{
}

protected void startApp()
{
Displayable cc=Display.getDisplay(this).getCurrent();
if(cc==null)
Display.getDisplay(this).setCurrent(play);
else
Display.getDisplay(this).setCurrent(cc);
}

protected void destroyApp(boolean parm1)
{
if(play!=null)
play.Release();
play=null;
}

public static void quitApp() {

instance.destroyApp(true);
instance.notifyDestroyed();
//System.gc();
}

}

canvas:

public class PlayCanvas extends Canvas implements Runnable{

GameMidletparent;

private boolean running;

private Image imgBody;
private Graphics gBody;

private int TIME=100;

private Thread thread=null;

private width ,height;

public PlayCanvas(GameMidlet parent) {

this.parent = parent;

width = getWidth();

height =getHeight();

imgBody = Image.createImage(width, height); // 缓冲界面
gBody = this.imgBody.getGraphics();

}

/*

线程启动

*/

public void start(){

if(!running){

thread = null;
System.gc();

running=true;

thread=new Thread(this);

thread.start();

}

}

/*

线程停止

*/

public void stop(){

if(running){

running = false;

}

}

/*

按键处理

*/

public void keyPressed(int keyCode) {

switch (keyCode) {
case KEY_UP_ARROW:

. .......................

break;

case KEY_DOWN_ARROW:

..............

break;

.......................

}

　　public void paint(Graphics g){

if (imgBody != null) {
g.drawImage(imgBody, 0, 0, Graphics.LEFT | Graphics.TOP); //游戏中的 精灵背景都画在imgBody上。
}

}

public void run(){

while(running){

long start = System.currentTimeMillis();

....... //运行一些逻辑和游戏界面的处理

int time = (int)(System.currentTimeMillis() - start);

if (time < TIME){

try {

Thread.sleep(TIME- time);

}catch (InterruptedException ex) {}

}else{

}

　｝

}

public void Release(){// 退出游戏 释放对象

thread = null;

imgBody = null;

System.gc();

}

}