cosumeapplet.java

这是我自己照着书上敲的

import java.applet.Applet;
/*
 * Created on 2007-9-14
 *
 * TODO To change the template for this generated file go to
 * Window - Preferences - Java - Code Style - Code Templates
 */
 import java.awt.*;
 import java.awt.event.*;
/**
 * @author Administrator
 *
 * TODO To change the template for this generated type comment go to
 * Window - Preferences - Java - Code Style - Code Templates
 */
public class CosumeApplet extends Applet {
	TextField input;
	public void init()
	{
	input=new TextField("",10);
	input.addKeyListener(new Listener());
	add(input);
	this.setBackground(Color.lightGray);
	}
class Listener extends KeyAdapter {
	public void keyPress(KeyEvent e) 
	{
		if(e.getKeyChar()<'0'||e.getKeyChar()>'9')
		{
			showStatus("Invalidate Input:"+e.getKeyChar());
			e.consume();
		}
		else
			showStatus("Input:"+e.getKeyChar());
	}
}
}