logindemo.java

Java面向对象编程(随书配套源代码) 阐述了面向对象编程的思想

package chapter14;
import javax.swing.*;
public class LoginDemo extends JFrame
{
	//声明组件
	JLabel lblTitle,lblUser,lblPass;
	JTextField txtUser;
	JPasswordField pwdPass;
	JButton btnLogin,btnExit;
	JPanel pnlMain;
	//构造方法
	public LoginDemo()
	{
		//调用父类构造函数
		super("用户登录");
		pnlMain=new JPanel();
		//设置JFrame的容器为pnlMain
		this.getContentPane().add(pnlMain);
		//实例化组件
		lblTitle=new JLabel(new ImageIcon("welcome.gif"));
		lblUser=new JLabel("用户名:");
		txtUser=new JTextField(12);
		lblPass=new JLabel("密码:");
		pwdPass=new JPasswordField(12);
		//"登录"按钮
		Icon imgLogin=new ImageIcon("login.gif");
		btnLogin=new JButton("登录(L)",imgLogin);
		btnLogin.setMnemonic('L');
		btnLogin.setToolTipText("点击登录");
		//"退出"按钮
		Icon imgExit=new ImageIcon("exit.gif");
		btnExit=new JButton("退出(X)",imgExit);
		btnExit.setMnemonic('X');
		btnExit.setToolTipText("退出登录");
		//添加组件到面板
		pnlMain.add(lblTitle);
		pnlMain.add(lblUser);
		pnlMain.add(txtUser);
		pnlMain.add(lblPass);
		pnlMain.add(pwdPass);
		pnlMain.add(btnLogin);
		pnlMain.add(btnExit);
		//设置窗口属性
		setSize(225,200);
		setResizable(false);
		setVisible(true);		
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	}
	//主方法 
	public static void main(String args[])
	{
			new LoginDemo();
	}
}