文本框TextBox类的应用

import javax.microedition.lcdui.*;import javax.microedition.midlet.MIDlet;import javax.microedition.midlet.MIDletStateChangeException;public class TextBoxDemo extends MIDlet implements CommandListener{private Display display=Display.getDisplay(this);private TextBox textBox;private Command cmdOK=new Command("写好了",Command.SCREEN,1);private Command cmdExit=new Command("不写了",Command.SCREEN,2);private Alert alert;public TextBoxDemo() {// TODO Auto-generated constructor stubtextBox=new TextBox("呆，输入电话号码","",11,TextField.PHONENUMBER);textBox.addCommand(cmdOK);textBox.addCommand(cmdExit);textBox.setCommandListener(this);}protected void destroyApp(boolean arg0) throws MIDletStateChangeException {// TODO Auto-generated method stub}protected void pauseApp() {// TODO Auto-generated method stub}protected void startApp() throws MIDletStateChangeException {// TODO Auto-generated method stubdisplay.setCurrent(textBox);}public void commandAction(Command arg0, Displayable arg1){// TODO Auto-generated method stubif(arg0==cmdOK){alert=new Alert("发送","",null,AlertType.INFO);alert.setTimeout(3000);alert.setString("正在发送……");display.setCurrent(alert, display.getCurrent());//将该对话框设置为当前的屏幕}else if(arg0==cmdExit){try {destroyApp(false);} catch (MIDletStateChangeException e) {// TODO Auto-generated catch blocke.printStackTrace();}notifyDestroyed();}}}