lifemidlet.java

来自「《J2ME实用教程》清华大学出版社出版」· Java 代码 · 共 54 行

package com.j2medev.chapter3;

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;

public class LifeMIDlet extends MIDlet implements CommandListener {
    
    private Display display = null;
    private MainCanvas canvas = null;
    private Command exitCommand = new Command("exit",Command.OK,2);
    
    public void startApp() {
        //第一次启动LifeMIDlet
        if(display == null){
            System.out.println("start up the MIDlet");
            display = Display.getDisplay(this);
            canvas = new MainCanvas(this);
            display.setCurrent(canvas);
        }else{
            System.out.println("Restart up the MIDlet");
        }
    }
    
    public void pauseApp() {
        canvas.release();
        //从中断中恢复LifeMIDlet,提供一个恢复选择界面
        PauseCanvas pause = new PauseCanvas(this);
        display.setCurrent(pause);
    }
    
    public void destroyApp(boolean unconditional) {
    }
    
    public void commandAction(Command cmd,Displayable displayable){
        if(cmd == exitCommand){
            exitMIDlet();
        }
    }
    
    public void release(){
        canvas.release();
    }
    //重新启动MainCanvas
    public void restart(){
        display.setCurrent(canvas);
        canvas.setRestart(true);
        canvas.restart();
    }
    public void exitMIDlet(){
        destroyApp(false);
        notifyDestroyed();
    }
}