我的程序
import java.awt.*;
public class Wendu1 {
    public static void main(String[] args){
        Frame f=new Frame("登录窗口");
        Label lab1=new Label("ID",Label.CENTER);
        Label lab2=new Label("密码",Label.CENTER);
        Button bun1=new Button("登录");
        Button bun2=new Button("取消");
        TextField tf1=new TextField(10);
        TextField tf2=new TextField(10);
        f.add(lab1);
        f.add(lab2);
        f.add(bun1);
        f.add(bun2);
        f.add(tf1);
        f.add(tf2);
        f.setLayout(null);
        lab1.setBounds(20,50,100,30);
        lab2.setBounds(20,80,100,30);
        tf1.setBounds(120,50,100,30);
        tf2.setBounds(120,80,100,30);
        bun1.setBounds(20,110,100,30);
        bun2.setBounds(120,110,100,30);
        f.setBounds(350,200,300,150);
        f.setVisible(true);
    }
}

楼上的,是不是增加        f.addWindowListener(new WindowAdapter(){
            @Override
            public void windowClosing(WindowEvent arg0) {
                // TODO Auto-generated method stub
                System.exit(0);
            }});
这个语句就可以了

不行啊
WindowAdapter 下面画曲线了