java登录窗口

java登录窗口 2007-06-15 15:21 import java.awt.*; import java.awt.event.*; import javax.swing.*; import java.util.*; class LoginWindow extends JDialog implements ActionListener { JPanel p1=new JPanel(); //定义并建立面板 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 txtPwd=new JPasswordField(15);//密码框 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(txtPwd); p4.add(ok);p4.add(cancel); ok.addActionListener(this); cancel.addActionListener(this); txtUserName.addActionListener(this); txtPwd.addActionListener(this); contentPane.add(p1); //将面板添加到内容面板 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(300,220); Dimension screen=Toolkit.getDefaultToolkit().getScreenSize(); setLocation((screen.width-300)/2,(screen.height-220)/2); setTitle("登录窗口"); 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()==txtPwd) //单击确定按钮后 { if(txtUserName.getText().trim().equals("wdx") && txtPwd.getText().trim().equals("wdx")) {dispose(); //关闭登录窗口 //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 { dispose(); System.exit(0); } else if(e.getSource()==txtUserName) //在用户名文本框按回车移动焦点到密码框 { txtPwd.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(); } }