itemstatelistenerdemo.java

来自「J2ME手机游戏开发技术详解随书光盘」· Java 代码 · 共 41 行

import javax.microedition.lcdui.*;
import javax.microedition.midlet.MIDlet;
public class ItemStateListenerDemo extends MIDlet implements CommandListener 
{
    private final static Command CMD_EXIT = new Command("Exit",Command.EXIT, 1);
    private Display display;
    private Gauge mGauge;
    private StringItem mStringItem;
    private Form mainForm;
    public ItemStateListenerDemo() {
        display = Display.getDisplay(this);
        mainForm = new Form("Gauge演示");
        mGauge = new Gauge("调节游戏难度",true, 5, 2);
        mainForm.append(mGauge);
        mStringItem = new StringItem("当前难度","2");
        mainForm.append(mStringItem);
        mainForm.addCommand(CMD_EXIT);
        mainForm.setCommandListener(this);
        ItemStateListener listener = new ItemStateListener(){
        public void itemStateChanged(Item item){
        if(item == mGauge){
        mStringItem.setText(""+mGauge.getValue());
        }
        }
        };
        mainForm.setItemStateListener(listener);
    }
    protected void startApp() {
        display.setCurrent(mainForm);
    }
    protected void destroyApp(boolean unconditional) {
    }
    protected void pauseApp() {
    }
    public void commandAction(Command c, Displayable d) {
        destroyApp(false);
        notifyDestroyed();
    }
}