Question

这是代码。我的主框架是orbital_app，我希望当我点击JButton（按钮）时，数据被保存，当前窗口关闭，另一个窗口orbital_app打开。

public class signup_try {

    private JFrame frame;
    private JTextField txtname;
    private JTextField textusername;
    private JTextField txtpass;
    private JTextField textmail;

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

    /**
     * Create the application.
     */
    public signup_try() {
        initialize();
    }

    Connection connection=null;

    /**
     * Initialize the contents of the frame.
     */
    private void initialize() {

        connection=dbase.dBase();
        frame = new JFrame();
        frame.setBounds(100, 100, 450, 300);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().setLayout(null);

        JLabel label = new JLabel("Orbital");
        label.setForeground(SystemColor.activeCaption);
        label.setFont(new Font("Arial Black", Font.BOLD, 17));
        label.setBounds(170, 11, 71, 25);
        frame.getContentPane().add(label);

        JLabel label_1 = new JLabel("Name:");
        label_1.setForeground(SystemColor.activeCaption);
        label_1.setFont(new Font("Arial Black", Font.PLAIN, 12));
        label_1.setBounds(21, 66, 46, 14);
        frame.getContentPane().add(label_1);

        txtname = new JTextField();
        txtname.setColumns(10);
        txtname.setBounds(102, 63, 200, 22);
        frame.getContentPane().add(txtname);

        textusername = new JTextField();
        textusername.setColumns(10);
        textusername.setBounds(102, 108, 200, 22);
        frame.getContentPane().add(textusername);

        txtpass = new JTextField();
        txtpass.setColumns(10);
        txtpass.setBounds(102, 150, 200, 22);
        frame.getContentPane().add(txtpass);

        textmail = new JTextField();
        textmail.setColumns(10);
        textmail.setBounds(102, 192, 200, 22);
        frame.getContentPane().add(textmail);

        JLabel label_2 = new JLabel("Username:");
        label_2.setForeground(SystemColor.activeCaption);
        label_2.setFont(new Font("Arial Black", Font.PLAIN, 12));
        label_2.setBounds(21, 111, 71, 14);
        frame.getContentPane().add(label_2);

        JLabel label_3 = new JLabel("Password:");
        label_3.setForeground(SystemColor.activeCaption);
        label_3.setFont(new Font("Arial Black", Font.PLAIN, 12));
        label_3.setBounds(21, 154, 71, 14);
        frame.getContentPane().add(label_3);

        JLabel label_4 = new JLabel("Email:");
        label_4.setForeground(SystemColor.activeCaption);
        label_4.setFont(new Font("Arial Black", Font.PLAIN, 12));
        label_4.setBounds(21, 196, 46, 14);
        frame.getContentPane().add(label_4);

        JButton button = new JButton("Sign Up");
        button.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {

try {

                    String query="insert into Users(Name, Username, Password, Email) values(?,?,?,?)";
                    PreparedStatement prepstat=connection.prepareStatement(query);
                    prepstat.setString(1, txtname.getText());
                    prepstat.setString(2, textusername.getText());
                    prepstat.setString(3, txtpass.getText());
                    prepstat.setString(4, textmail.getText());

                    prepstat.execute();

                    JOptionPane.showMessageDialog(null, "Data saved");



                    prepstat.close();

                } catch (SQLException e) {
                    JOptionPane.showMessageDialog(null, e);
                }

我收到错误消息The method setVisible(boolean) is undefined for the type orbital_app。我该怎么做才能解决这个问题？在这里，我想关闭此当前帧（signup_try）并转到其他帧（orbital_app）.. setVisible带有下划线红色并显示"The method setVisible(boolean) is undefined for the type orbital_app"。
```
                frame.dispose();
                orbital_app orb=new orbital_app();
                orb.setVisible(true);


            }
        });
        button.setBounds(170, 239, 91, 23);
        frame.getContentPane().add(button);
    }
```
}

Orbital_app代码（在此代码中setVisible正常工作，没有任何错误）：

package project;

import java.awt.EventQueue;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingConstants;

import java.awt.Font;

import java.awt.SystemColor;

import javax.swing.JButton;
import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;
import java.awt.Color;
import javax.swing.UIManager;

public class orbital_app{

    private JFrame frame;

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



    /**
     * Create the application.
     */




    public orbital_app() {
        initialize();
    }

    /**
     * Initialize the contents of the frame.
     */
    private void initialize() {
        frame = new JFrame();
        frame.getContentPane().setBackground(UIManager.getColor("Button.background"));
        frame.setResizable(false);
        frame.setBounds(100, 100, 450, 260);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().setLayout(null);

        JLabel toplbl = new JLabel("Orbital");
        toplbl.setForeground(SystemColor.activeCaption);
        toplbl.setFont(new Font("Arial Black", Font.BOLD, 17));
        toplbl.setVerticalAlignment(SwingConstants.TOP);
        toplbl.setBounds(182, 11, 71, 25);
        frame.getContentPane().add(toplbl);

        JLabel infolbl = new JLabel("Multipurpose app ==  orbital 1.0\r\n");
        infolbl.setFont(new Font("Arial", Font.PLAIN, 11));
        infolbl.setForeground(SystemColor.activeCaption);
        infolbl.setBounds(138, 47, 165, 25);
        frame.getContentPane().add(infolbl);

        JButton signup_btn = new JButton("Sign Up");
        signup_btn.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                frame.dispose();
                signup_form sup_for=new signup_form();

3.setVisible在这里工作

                sup_for.setVisible(true);
            }
        });
        signup_btn.setFont(new Font("Arial", Font.PLAIN, 11));
        signup_btn.setForeground(SystemColor.activeCaption);
        signup_btn.setBounds(61, 133, 91, 23);
        frame.getContentPane().add(signup_btn);

        JButton signin_btn = new JButton("Sign In");
        signin_btn.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {

                frame.dispose();
                signin_form log_for=new signin_form();

4.此处也是

                log_for.setVisible(true);
            }
        });
        signin_btn.setFont(new Font("Arial", Font.PLAIN, 11));
        signin_btn.setForeground(SystemColor.activeCaption);
        signin_btn.setBounds(285, 133, 91, 23);
        frame.getContentPane().add(signin_btn);

        JLabel notelbl = new JLabel("note: click Sign Up for new account or Sign In for existing account.");
        notelbl.setHorizontalAlignment(SwingConstants.CENTER);
        notelbl.setBounds(10, 199, 406, 25);
        frame.getContentPane().add(notelbl);
    }



}

Answer 1

我遇到了同样的问题，它是通过排除JFrame类来解决的。您的类应该扩展JFrame，因为setVisible（）方法属于JFrame类。

Answer 2

您的代码似乎存在一些问题。

最重要的是：您的计划中有多个入口点您应该只在应用程序中有一个public static void main(String[] args) ...函数，即“程序启动”。

您收到的错误消息（The method setVisible(boolean) is undefined for the type orbital_app）来自于orbital_app类没有setVisible函数，其成员之一，但是没有物质

您的orbital_app有一位JFrame的私人会员，这使您可以通过访问该框架来调用JFrames内的orbital_app方法，但是你无法从外面到达它看来你混淆了继承和所有权。

如果您希望orbital_app课程为JFrame，则需要继承JFrame。否则，您可以实施您希望为其他课程公开的方法或者您可以为私有JFrame对象创建一个getter，以便您可以从外部访问它。

对于orbital_app类型，方法setVisible（boolean）未定义

}

2 个答案: