我们如何解决heap size不够的事情呢？手机是不能够改变其heap size的，我们只有想办法控制heap memory的使用。最直观的做法就是：存储内存与运算内存的优化使用，当运算内存需要资源时从存储内存中调用，需要新的资源时，就把不需要的释放掉。下面我就结合一段代码解释我们是如何制作Loading状态的。
众所周知，Java是内置多线程的，我们可以使用两个线程来解决loading的问题，一个读资源的线程，一个绘制资源的线程。程序代码：
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
/**
* Loading演示
* @author gaogao
* */
class MainCanvas
extends Canvas
implements Runnable {
//程序状态
static final int LOADING = 0;
static final int GAMEING = 1;
//程序状态控制器
int state = LOADING;
//主线程
Thread thread = null;
//是否loading完毕，
boolean isLoaded = false;
//内部类，新开读取资源的 线程
class Loading
implements Runnable {
//内线程
Thread innerThread = null;
public Loading() {
innerThread = new Thread(this);
innerThread.start();
}
int counter = 100;
public void run() {
//模拟读取资源
//把下面的东西改成读取资源的代码即可
while (counter > 0) {
counter--;
try {
Thread.sleep(20);
}
catch (Exception ex) {}
}
//loading结束
isLoaded = true;
}
}
Loading loading = null;
public MainCanvas() {
loading = new Loading();
thread = new Thread(this);
thread.start();
}
int loadingCounter = 0;
//绘制..
public void paint(Graphics g) {
g.setColor(0);
g.fillRect(0, 0, getWidth(), getHeight());
switch (state) {
case LOADING: {
g.setColor(0XFFFFFF);
g.drawString("LOADING" + ">>>>>".substring(0, loadingCounter),
getWidth() >> 1, getHeight() >> 1,
Graphics.HCENTER | Graphics.TOP);
loadingCounter = ++loadingCounter % 5;
}
break;
case GAMEING: {
g.setColor(0XFFFFFF);
g.drawString("GAME", getWidth() >> 1, getHeight() >> 1,
Graphics.HCENTER | Graphics.TOP);
}
break;
}
}
public void run() {
while (true) {
try {
Thread.sleep(100);
}
catch (Exception ex) {
}
if (isLoaded) {
loading = null;
state = GAMEING;
}
repaint(0, 0, getWidth(), getHeight());
serviceRepaints();
}
}
}
public class Main
extends MIDlet {
MainCanvas mc;
public void startApp() {
if (mc == null) {
mc = new MainCanvas();
Display disp = Display.getDisplay(this);
disp.setCurrent(mc);
}
}
public void destroyApp(boolean bool) {}
public void pauseApp() {}
}
</td>
</tr>
</table>
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