Swing做的简单登陆界面

【要点】

Box的布局；

窗体的居中；

登陆完成后dispose方法关闭窗体；

import java.awt.Container;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.*;

import com.kx.Adapter.*;
import com.kx.SetupGUI.AppMainFrame;

public class LoginMainFrame extends JFrame {

	private static final long serialVersionUID = 1L;
	private final static int HEIGHT=150;
	private final static int WIDTH=250;
	
	private String inUsername,inPassword;
	
	public LoginMainFrame(){
		setTitle("登陆窗口");//同super("登录窗口")
		this.setResizable(false);//也可以不用this,以后都不用
		
		SetupUI();
		MyWindowAdapter mwa=new MyWindowAdapter();
		addWindowListener(mwa);   //指的是super或者LoginMainFrame
		Dimension screenSize=Toolkit.getDefaultToolkit().getScreenSize();
		setLocation(screenSize.width/2-WIDTH/2, screenSize.height/2-HEIGHT/2);
		setSize(WIDTH, HEIGHT);
	}
	
	public void SetupUI(){
		//Pane:镶板；ContentPane：内容镶板
		Container container=getContentPane();   //JFrame.getContentPane();
		//container.setLayout(new GridLayout());
		container.setLayout(new FlowLayout());
		
		Box hor1=Box.createHorizontalBox();
		Box hor2=Box.createHorizontalBox();
		Box hor3=Box.createHorizontalBox();
		Box hor4=Box.createHorizontalBox();
		Box hor5=Box.createHorizontalBox();
		Box ver1=Box.createVerticalBox();
		Box ver2=Box.createVerticalBox();
		
		JLabel lblTitle=new JLabel("登陆窗口");
		lblTitle.setFont(new Font("",Font.BOLD,18));
		container.add(hor1);
		hor1.add(lblTitle);
		
		JLabel lblUserID=new JLabel("登录名：");
		final JTextField txtUserID=new JTextField();
		hor2.add(lblUserID);
		hor2.add(txtUserID);
		hor2.setSize(300, 80);
		
		JLabel lblPassword=new JLabel("密    码：");
		final JPasswordField txtPassword=new JPasswordField();
		hor3.add(lblPassword);
		hor3.add(txtPassword);
		hor3.setSize(300, 80);
		
		JButton btnSubmit=new JButton("确认");
		btnSubmit.addActionListener(new ActionListener() {
			
			@Override
			public void actionPerformed(ActionEvent e) {
				System.out.println("确认");
				inUsername=txtUserID.getText();
				inPassword=txtPassword.getText();
				LoginCheck(inUsername,inPassword);	
			}
		});
		JButton btnClear=new JButton("清空");
		btnClear.addActionListener(new ActionListener() {
			
			@Override
			public void actionPerformed(ActionEvent e) {
				System.out.print("清空");
				txtUserID.setText("");
				txtPassword.setText("");	
			}
		});
		hor4.add(btnSubmit);
		hor4.add(btnClear);
		
		ver1.add(hor1);
		ver1.add(hor2);
		ver1.add(hor3);
		ver1.add(hor4);
		
		container.add(ver1);
	}
	public void LoginCheck(String UserID,String Password){
		if(UserID.equals("")||UserID==null){
			JOptionPane.showMessageDialog(null,"没有输入用户名。","登陆系统：提示",JOptionPane.ERROR_MESSAGE);	
		}
		else if(Password.equals("")||Password==null){
			JOptionPane.showMessageDialog(null,"没有输入密码。","登陆系统：提示",JOptionPane.ERROR_MESSAGE);	
		}
		else if(UserID.equals("admin")&&Password.equals("admin")){
			System.out.print("成功");
			AppMainFrame amf= new AppMainFrame();
			amf.F.setVisible(true);
			this.dispose();  //用于登陆后关闭。
		}
	}
	public static void main(String[] args) {
		LoginMainFrame lmf=new LoginMainFrame();
		lmf.setVisible(true);
	}

}