Java Swing中JDialog实现用户登陆UI示例

本文实例讲述了Java Swing中JDialog实现用户登陆UI。分享给大家供大家参考，具体如下：

JDialog是一种对话框组件，它常常与JOptionPane配合使用。JOptionPane提供对话框内部的消息、按钮等内容，JDialog提供对话框窗体，提供模态/非模态等属性。JDialog与Jframe在外观上的区别在于，它没有最大化/最小化按钮。如下图所示：

JDialog窗体

 点击File-》connect之后弹出登陆窗口：

Jframe窗体

在下面的demo中，演示了JDialog构造登录窗体，以及从窗体中获得数据的方法。

LoginDemoStart.java

package awtDemo;
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;

@SuppressWarnings("serial")
class LoginDemoStart extends Jframe{
  
  private Jtextarea textarea;
  private PasswordChooser passwordChooser ;
  public LoginDemoStart(){
    //构造菜单栏
    JMenuBar mbar = new JMenuBar();
    setJMenuBar(mbar);
    JMenu fileMenu = new JMenu("File");
    JMenuItem connectItem = new JMenuItem("connect");
    connectItem.addActionListener(new ActionListener(){
      public void actionPerformed(ActionEvent e) {
 // TODO Auto-generated method stub
 //if 1st time,construct a dialog
 passwordChooser = new PasswordChooser(LoginDemoStart.this);
 passwordChooser.setVisible(true);
 if(passwordChooser.isLogedIn())
 {
   User u = passwordChooser.getUser();
   textarea.append("Username = " + u.getName() + ", Password = " + new String(u.getPassword()) + "n");
 }
      }
    });
    JMenuItem exitItem = new JMenuItem("exit");
    exitItem.addActionListener(new ActionListener() {
      @Override
      public void actionPerformed(ActionEvent e) {
 // TODO Auto-generated method stub
 System.exit(0);
      }
    });
    mbar.add(fileMenu);
    fileMenu.add(connectItem);
    fileMenu.add(exitItem);
    //添加文本区域
    textarea = new Jtextarea();
    add(new JScrollPane(textarea), BorderLayout.CENTER);
    //设置窗体属性
    setTitle("LoginDemoStart - www.jb51.net");
    setSize(300,200);
    setLocationRelativeTo(null);
  }
  public static void main(String[] args) {
    // TODO Auto-generated method stub
    LoginDemoStart loginDemoStart = new LoginDemoStart();
    loginDemoStart.setVisible(true);
  }
}

PasswordChooser.java

package awtDemo;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

@SuppressWarnings("serial")
class PasswordChooser extends JDialog{
  private JTextField username ;
  private JPasswordField password ;
  private JButton okButton ;
  private JButton cancelButton ;
  private boolean isLogedIn = false;
  public PasswordChooser(frame parent){
    super(parent, true);
    //本UI包含2个panel
    JPanel inputPanel = new JPanel();
    JPanel buttonPanel = new JPanel();
    //构造inputPanel    
    inputPanel.setLayout(new GridLayout(2,2));
    inputPanel.add(new JLabel("Useername:"));
    username = new JTextField();
    username.setColumns(10);
    password = new JPasswordField();
    password.setColumns(10);
    inputPanel.add(username);
    inputPanel.add(new JLabel("Password:"));
    inputPanel.add(password);
    inputPanel.setBorder(BorderFactory.createEmptyBorder(10, 5, 10, 5));
    //构造buttonPanel    
    okButton = new JButton("OK");
    okButton.addActionListener(new ActionListener() {
      @Override
      public void actionPerformed(ActionEvent e) {
 // TODO Auto-generated method stub
 isLogedIn = true;
 setVisible(false);
      }
    });
    cancelButton = new JButton("Cancel");
    cancelButton.addActionListener(new ActionListener() {
      @Override
      public void actionPerformed(ActionEvent e) {
 // TODO Auto-generated method stub
 setVisible(false);
      }
    });
    buttonPanel.add(okButton);
    buttonPanel.add(cancelButton);
    buttonPanel.setBorder(BorderFactory.createEmptyBorder(10, 5, 10, 5));
    //构造主框架
    setLayout(new BorderLayout());
    getContentPane().add(inputPanel, BorderLayout.NORTH);
    getContentPane().add(buttonPanel, BorderLayout.SOUTH);
    //设置窗体属性
    setTitle("PasswordChooser - www.jb51.net");
    setLocationRelativeTo(inputPanel);
    //setPreferredSize(new Dimension(300, 200));
    pack();
    //System.out.println(getPreferredSize());
  }
  public void setUser(User u){
    username.setText(u.getName());
  }
  public User getUser(){
    return new User(username.getText(), password.getPassword());
  }    
  public boolean isLogedIn(){
    return isLogedIn;
  }    
  public static void main(String[] args) {
    // TODO Auto-generated method stub
  }
}

User.java

package awtDemo;

class User{
  private String name;
  private char[] password;
  public User(String aName, char[] aPassword){
     name = aName;
     password = aPassword;
  }
  public String getName(){
    return name;
  }
  public char[] getPassword(){
    return password;     
  }
  public void setName(String aName){
    name = aName;
  }
  public void setPassword(char[] aPassword){
    password = aPassword;
  }
}

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