第二篇学习笔记

import java.awt.EventQueue;
import java.awt.GridLayout;
import java.awt.Label;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JPasswordField;

public class D2 {
public static void main(String[] args){
EventQueue.invokeLater(new Runnable(){
public void run(){
JFrame frame = new Register();
frame.setTitle("班级管理系统");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
});
}
}
class Register extends JFrame{
private static final long serialVersionUID = 1L;
private JPanel all = new JPanel();
private JComboBox jcb = new JComboBox();
private JPasswordField pwf = new JPasswordField(10);

private JButton confirm = new JButton("确定");
private JButton cancel = new JButton("取消");

Register(){
GridLayout Gl = new GridLayout(3,2,30,10);

all.setLayout(Gl);

addU();
addP();
addB();
add(all);
pack();
}
private void addU(){
jcb.addItem("导员");
jcb.addItem("班长");
jcb.addItem("学委");
jcb.addItem("团支");
jcb.addItem("学生");
jcb.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent a3){

}
});
all.add(new Label("请输入用户名"));
all.add(jcb);
}
private void addP(){
all.add(new Label("请输入密码"));
all.add(pwf);
}
private void addB(){
confirm.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent a1) {
String p = new String(pwf.getPassword());
String s = (String)jcb.getSelectedItem();
JOptionPane.showMessageDialog(null,"你选择的职务:"+s+"  你输入的密码:"+p);
}
});
cancel.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent a2){
JOptionPane.showMessageDialog(null,"退出");
dispose();
}
});
all.add(confirm);
all.add(cancel);
}

}