java - 无法使 JDialog 模式化

Question

我试图在单击“注册”按钮时打开一个新的 JDialog..
但是我无法使 JDialog 模态..
我试过 setModal(true) 和 setModalityType(ModalityType.DOCUMENT_MODAL);但运气不好..(我正在使用 Eclipse 的 WindowBuilder 插件)
P.S: 我是 JAVA 新手..
这是我的代码...

import java.awt.BorderLayout;
import java.awt.Dialog.ModalityType;
import java.awt.EventQueue;
import java.awt.FlowLayout;
import java.awt.Frame;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JScrollPane;
import javax.swing.JLabel;
import java.awt.Color;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import javax.swing.ImageIcon;
import javax.swing.JDialog;
import javax.swing.JList;
import javax.swing.JOptionPane;
import javax.swing.JTextField;
import javax.swing.JPasswordField;
import javax.swing.JComboBox;
import javax.swing.JButton;
import javax.xml.ws.handler.MessageContext;


public class loginpage extends JFrame {

    private JPanel contentPane;
    private JTextField userid;
    private JPasswordField password;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    loginpage frame = new loginpage();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the frame.
     */
    public loginpage() {
        super("User Login");
        setResizable(false);
        setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        setBounds(400, 200, 550, 370);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        contentPane.setLayout(null);
        setContentPane(contentPane);

        JLabel label = new JLabel("Please enter your login credentials...");
        label.setFont(new Font("Times New Roman", Font.PLAIN, 25));
        label.setForeground(Color.BLUE);
        label.setBounds(79, 11, 400, 61);
        contentPane.add(label);

        JLabel lblLoginId = new JLabel("User ID :");
        lblLoginId.setFont(new Font("Tahoma", Font.PLAIN, 12));
        lblLoginId.setBounds(159, 142, 71, 17);
        contentPane.add(lblLoginId);

        JLabel lblUserType = new JLabel("User Type :");
        lblUserType.setFont(new Font("Tahoma", Font.PLAIN, 12));
        lblUserType.setBounds(159, 102, 85, 17);
        contentPane.add(lblUserType);

        JLabel lblPassword = new JLabel("Password :");
        lblPassword.setFont(new Font("Tahoma", Font.PLAIN, 12));
        lblPassword.setBounds(159, 188, 96, 14);
        contentPane.add(lblPassword);

        userid = new JTextField();
        userid.setBounds(254, 141, 114, 20);
        contentPane.add(userid);
        userid.setColumns(10);

        password = new JPasswordField();
        password.setBounds(254, 186, 114, 20);
        contentPane.add(password);

        JComboBox usertype = new JComboBox();
        usertype.setBounds(254, 101, 89, 20);
        contentPane.add(usertype);
        usertype.addItem("Admin");
        usertype.addItem("Employee");

        JButton btnLogin = new JButton("Login");
        btnLogin.setBounds(254, 228, 71, 23);
        contentPane.add(btnLogin);

        JLabel lblNewEmployeeRegister = new JLabel("New employee? ");
        lblNewEmployeeRegister.setForeground(Color.RED);
        lblNewEmployeeRegister.setBounds(296, 304, 114, 14);
        contentPane.add(lblNewEmployeeRegister);

        JButton btnRegister = new JButton("Register Here");
        btnRegister.setBounds(398, 301, 126, 20);
        contentPane.add(btnRegister);

        ImageIcon myicon = new ImageIcon("src\\logo.gif");
        JLabel iconlabel = new JLabel(myicon);
        iconlabel.setBounds(0, 233, 103, 99 );
        iconlabel.setIcon(myicon);
        contentPane.add(iconlabel);


        //Adding Listeners to buttons

        //Login Button Listener
        btnLogin.addActionListener(new ActionListener()
        {

            //Making the Connection and registering the Drivers
            @Override
            public void actionPerformed(ActionEvent arg0) {

            }//actionPerformed ends here
        });//Login Button Listener ends here


        //Register Button Listener
        btnRegister.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                JDialog jd=new JDialog(loginpage.this,"User Registration");
                jd.setLayout(null);
                jd.setVisible(true); 
                jd.setBounds(400,300, 479, 329);  
                jd.setResizable(false);
                setLocationRelativeTo(loginpage.this);
                jd.setModal(true);

                JLabel lblFillUpThe = new JLabel("Fill up the form to register");
                lblFillUpThe.setForeground(Color.BLUE);
                lblFillUpThe.setFont(new Font("Times New Roman", Font.PLAIN, 25));
                lblFillUpThe.setBounds(93, 11, 400, 61);
                jd.add(lblFillUpThe);

                JLabel lblUserId = new JLabel("Type in a User ID :");
                lblUserId.setFont(new Font("Tahoma", Font.PLAIN, 12));
                lblUserId.setBounds(77, 96, 104, 14);
                jd.add(lblUserId);

                JTextField newid = new JTextField();
                newid.setBounds(236, 94, 122, 20);
                jd.add(newid);
                newid.setColumns(10);

                JLabel lblTypeA = new JLabel("Type in a new Password :");
                lblTypeA.setFont(new Font("Tahoma", Font.PLAIN, 12));
                lblTypeA.setBounds(77, 142, 142, 14);
                jd.add(lblTypeA);

                JPasswordField newpass = new JPasswordField();
                newpass.setBounds(236, 140, 122, 20);
                jd.add(newpass);

                JLabel lblConfirmThePassword = new JLabel("Confirm the Password :");
                lblConfirmThePassword.setFont(new Font("Tahoma", Font.PLAIN, 12));
                lblConfirmThePassword.setBounds(77, 189, 130, 14);
                jd.add(lblConfirmThePassword);

                JPasswordField confpass = new JPasswordField();
                confpass.setBounds(236, 187, 122, 20);
                jd.add(confpass);

                JButton reg = new JButton("Register");
                reg.setBounds(239, 237, 89, 23);
                jd.add(reg);



                reg.addActionListener(new ActionListener() {

                    @Override
                    public void actionPerformed(ActionEvent arg0) {
                        JOptionPane.showMessageDialog(getParent(), "User Registered Successfully..!!", "Successful",JOptionPane.INFORMATION_MESSAGE);

                    }
                });
            }
        });//Register Button Listener ends here

    }
}

Answer 1

在尝试使对话框可见之前，先尝试将对话框设置为模态。一旦对话框可见，您就无法更改模态状态...

JDialog jd=new JDialog(loginpage.this,"User Registration");
jd.setModal(true);
jd.setLayout(null); // THIS IS A BAD IDEA //
jd.setLocationRelativeTo(null);
// This is somewhat pointless, you've set relative location, but know overridden it...
// You should also be relying on the layout manager and pack to determine the size...
jd.setBounds(400,300, 479, 329); 
jd.setResizable(false);
setLocationRelativeTo(loginpage.this);

// Add you other components

jd.setVisible(true);