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 stub
		textBox=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 stub
		display.setCurrent(textBox);
	}
	public void commandAction(Command arg0, Displayable arg1)
	{
		// TODO Auto-generated method stub
		if(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 block
				e.printStackTrace();
			}
			notifyDestroyed();
		}
	}
}