1 import javax.microedition.lcdui.Command;
2 import javax.microedition.lcdui.CommandListener;
3 import javax.microedition.lcdui.Display;
4 import javax.microedition.lcdui.Displayable;
5 import javax.microedition.lcdui.TextBox;
6 import javax.microedition.midlet.MIDlet;
7 import javax.microedition.midlet.MIDletStateChangeException;
8
9
10 public class main extends MIDlet implements CommandListener {
11
12 private Command exitCom;
13 private Display ds;
14 private TextBox tb;
15
16 //构造函数
17 public main() {
18 // TODO Auto-generated constructor stub
19 ds=Display.getDisplay(this);//创建Display类一个实体
20 exitCom=new Command("Exit",Command.EXIT,1);//创建Command对象一个实体，并设置Exit命令用于退出这个MIDlet
21 tb=new TextBox("Hellow MIDlet","Hellow World",15,0);//创建用来输出东西的TextBox对象
22 tb.addCommand(exitCom);//使Command对象和TextBox关联起来
23 tb.setCommandListener(this);//当TextBox显示在屏幕上时，使CommandListener响应发生的事件
24 }
25
26 protected void destroyApp(boolean arg0) throws MIDletStateChangeException {
27 // TODO Auto-generated method stub
28
29 }
30
31 //当系统要求MIDlet暂停时调用
32 protected void pauseApp() {
33 // TODO Auto-generated method stub
34
35 }
36
37 //第一次启动或者暂停后重启时由系统调用startApp()方法
38 protected void startApp() throws MIDletStateChangeException {
39 // TODO Auto-generated method stub
40 ds.setCurrent(tb);//将构造函数中的TextBox设置为当前的屏幕
41 }
42
43 //用户触发任何Command是，做出回应，系统会自动调用这个方法
44 public void commandAction(Command arg0, Displayable arg1) {
45 // TODO Auto-generated method stub
46 if(arg0==exitCom){
47 try {
48 destroyApp(false);
49 notifyDestroyed();
50 } catch (MIDletStateChangeException e) {
51 // TODO Auto-generated catch block
52 e.printStackTrace();
53 }
54 }
55 }
56
57 }
