customitemdemo.java

来自「j2me学习 简单例子」· Java 代码 · 共 89 行

package example.demoseniorui.custom;

import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Form;
import javax.microedition.lcdui.TextField;
import javax.microedition.midlet.MIDlet;
import javax.microedition.midlet.MIDletStateChangeException;

/**
 * <p>J2ME CustomItem Demo</p>
 * 
 * @author 刘光辉
 * @version 2009.02.01
 */
public class CustomItemDemo extends MIDlet implements CommandListener {

	private static final Command CMD_EXIT = new Command("退出",Command.EXIT,1);
	private Display display;
	private boolean firstTime;
	private Form mainForm;
	
	/**
	 * <p>CustomItemDemo的构造函数</p>
	 */
	public CustomItemDemo() {
		firstTime = true;
		mainForm = new Form("Custom Item");
	}
	
	/**
	 * <p>启动程序,使MIDlet处于active状态</p>
	 * <p>在这个方法里声明了一个Form,用来放置Custom Item</p>
	 * @see javax.microedition.midlet.MIDlet#startApp()
	 */
	protected void startApp() throws MIDletStateChangeException {
		if(firstTime){
			display = Display.getDisplay(this);
			
			mainForm.append(new TextField("UpperItem",null,10,0));
			mainForm.append(new Table("Table",Display.getDisplay(this)));
			mainForm.append(new TextField("LowerItem",null,10,0));
			mainForm.addCommand(CMD_EXIT);
			mainForm.setCommandListener(this);
			
			firstTime = false;
		}
		display.setCurrent(mainForm);
	}

	/**
	 * <p>暂停程序,使MIDlet处于pause状态</p>
	 * @see javax.microedition.midlet.MIDlet#pauseApp()
	 */
	protected void pauseApp() {

	}
	
	/**
	 * <p>销毁程序,使MIDlet处于destroyed状态</p>
	 * 
	 * @param boolean unconditional 
	 * <ul>true 释放资源保存数据进入destroyed状态,false 抛出异常保持当前状态</ul>
	 * @see javax.microedition.midlet.MIDlet#destroyApp(boolean)
	 */
	protected void destroyApp(boolean arg0) throws MIDletStateChangeException {

	}

	/**
	 * <p>命令处理函数,实现CommandListener接口</p>
	 * @param Command cmd 命令对象
	 * @param Displayable d 被放置到显示屏显示的对象
	 */
	public void commandAction(Command cmd, Displayable d) {
		if(cmd == CMD_EXIT){
            try {
				destroyApp(false);
			} catch (MIDletStateChangeException e) {
				e.printStackTrace();
			}
            notifyDestroyed();
		}
	}

}