package cn.it_08;
import java.awt.FlowLayout;
import java.awt.Frame;
import java.awt.Label;
import java.awt.TextField;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
public class FrameDemo {
/**
* @param args
* 你输入的如果是非数字字符，就取消你键盘录入的效果。
*/
public static void main(String[] args) {
Frame f=new Frame();
f.setBounds(100,200,300,400);
f.setLayout(new FlowLayout());
Label label = new Label("请输入你的QQ号码，不能是非数字，不信你试试");
TextField tf = new TextField(40);
f.add(label);
f.add(tf);
tf.addKeyListener(new KeyAdapter() {
@Override
public void keyPressed(KeyEvent e) {
char ch =e.getKeyChar();
if(!(ch>='0' && ch<='9')){
e.consume();
}}
});
f.addWindowListener(new WindowAdapter() {
@Override
public void windowClosing(WindowEvent ee) {
// TODO Auto-generated method stub
//super.windowClosing(e);
System.exit(0);
}
});
f.setVisible(true);
}
}
哪儿出错了呢