mainmenu.java

本程序用JavaME语言描述了一个运行在手机上的电子书系统

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.Image;
import javax.microedition.lcdui.ImageItem;
import javax.microedition.lcdui.Item;
import javax.microedition.lcdui.ItemCommandListener;
import javax.microedition.lcdui.StringItem;



public class MainMenu extends Form implements ItemCommandListener,
		CommandListener {															//主界面
	
	private static final Command CMD_EXIT = new Command ("退出",Command.EXIT,1);
	private final static Command CMD_GO = new Command("进入",Command.ITEM,2);
	
	private final StringItem  itemHis = new StringItem(" ","历史",Item.BUTTON);
	private final StringItem  itemEnt = new StringItem(" ","打开",Item.BUTTON);
	private final StringItem  itemOpt = new StringItem(" ","选项",Item.BUTTON);
	private final StringItem  itemAbout = new StringItem(" ","关于",Item.BUTTON);
	private ImageItem logo = null;
	
	private TxtReader bookReader;
	
	public MainMenu(TxtReader tr){
		super("主界面");
		bookReader = tr;
		Image logoImage = null;
		try{
			logoImage = Image.createImage("/logo/logo.png");
		} catch(Exception e){
			e.printStackTrace();
		}
		logo = new ImageItem(null,logoImage,Item.LAYOUT_CENTER,null);
		
		this.addCommand(CMD_EXIT);
		this.setCommandListener(this);
		
        //设置位置
		itemHis.setLayout(Item.LAYOUT_CENTER);
        itemEnt.setLayout(Item.LAYOUT_CENTER);
        itemOpt.setLayout(Item.LAYOUT_CENTER);
        itemAbout.setLayout(Item.LAYOUT_CENTER);
        this.append(logo);
		this.append(itemHis);
		itemHis.setDefaultCommand(CMD_GO);
        itemHis.setItemCommandListener(this);
		this.append(itemEnt);
		itemEnt.setDefaultCommand(CMD_GO);
		itemEnt.setItemCommandListener(this);
		this.append(itemOpt);
		itemOpt.setDefaultCommand(CMD_GO);
		itemOpt.setItemCommandListener(this);
		this.append(itemAbout);
		itemAbout.setDefaultCommand(CMD_GO);
		itemAbout.setItemCommandListener(this);
	}

	public void commandAction(Command c, Item item) {
		if(c == CMD_GO){
			if(item == itemHis){
				new Thread(new Runnable(){
					public void run(){
						Display.getDisplay(bookReader).setCurrent(bookReader.getDisplayable(TxtReader.HISTORYRECORDLIST));
					}
				}).start();
			}else if(item == itemEnt){
				new Thread(new Runnable(){
					public void run(){
						TxtFileList TFL = (TxtFileList)bookReader.getDisplayable(TxtReader.TXTFILELIST);
						TFL.showList();
					}
				}).start();
			}else if(item == itemAbout){
				new Thread(new Runnable(){
					public void run(){
						Display.getDisplay(bookReader).setCurrent(bookReader.getDisplayable(TxtReader.ABOUTMENU));
					}
				}).start();
			}else{
				new Thread(new Runnable(){
					public void run(){
						Display.getDisplay(bookReader).setCurrent(bookReader.getDisplayable(TxtReader.SETTING));
					}
				}).start();
			}
		}
	}

	public void commandAction(Command c, Displayable displayable) {
		if(c == CMD_EXIT){
			try{
				bookReader.destroyApp(false);
			}
			catch(Exception e){e.printStackTrace();}
			bookReader.notifyDestroyed();
		}
	}

}