2-3登录窗口

import java.awt.*; import java.awt.event.*; import javax.swing.*; import java.util.*; class LoginWindow extends JDialog implements ActionListener{ JPanel p1=new JPanel(); JPanel p2=new JPanel(); JPanel p3=new JPanel(); JPanel p4=new JPanel(); JPanel p5=new JPanel(); JTextField txtUserName=new JTextField(15);//用户名文本框 JPasswordField txtPassWord=new JPasswordField(15);//密码域 JButton ok=new JButton("确定"); JButton cancel=new JButton("取消"); public LoginWindow(){ setModal(true);//设置模态 setBackground(Color.LIGHT_GRAY);//设置背景色 Container contentPane=this.getContentPane();//取出内容面板 contentPane.setLayout(new GridLayout(5,1));//设置布局为5行1列 p2.add(new JLabel("用户名:")); p2.add(txtUserName);//将组件添加到中间容器 p3.add(new JLabel("密 码:")); p3.add(txtPassWord); p4.add(ok);p4.add(cancel); ok.addActionListener(this);//注册事件接听者 cancel.addActionListener(this); txtUserName.addActionListener(this); txtPassWord.addActionListener(this); contentPane.add(p1); contentPane.add(p2); contentPane.add(p3); contentPane.add(p4); contentPane.add(p5); setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);//设置自动关闭窗口 setSize(300,200); Dimension screen=Toolkit.getDefaultToolkit().getScreenSize(); setLocation((screen.width-300)/2,(screen.height-220)/2); setTitle("登陆窗口"); setResizable(false);//不让用户改变窗口大小 setVisible(true); } public void actionPerformed(ActionEvent e){ if(e.getSource()==ok||e.getSource()==txtPassWord){ if(txtUserName.getText().trim().equals("ZGD")&&txtPassWord.getText().trim().equals("100")){ dispose();//关闭登陆窗口 new MainWindow();//调出主窗口 } else{ JOptionPane.showMessageDialog(null,"用户名或密码错误!"); txtUserName.requestFocus();//设置焦点 txtUserName.setSelectionStart(0);//设置选中文本开始位置 txtUserName.setSelectionEnd(txtUserName.getText().length()); } } else if(e.getSource()==cancel){//单击取消按钮 dispose();//关闭程序 System.exit(0);//退出程序 } else if(e.getSource()==txtUserName)//在用户名文本框按回车焦点移到密码域 txtPassWord.requestFocus(); } public static void main(String args[]){ JDialog.setDefaultLookAndFeelDecorated(true); Font font=new Font("JFrame",Font.PLAIN,14); Enumeration keys=UIManager.getLookAndFeelDefaults().keys(); while(keys.hasMoreElements()){ Object key=keys.nextElement(); if(UIManager.get(key) instanceof Font)UIManager.put(key,font); } new LoginWindow(); } }