JTable未显示在JFrame（Java）上

Question

我有一个问题，JFrame没有显示JTable添加到它。我已经尝试过getContentPane().add(..)，我已切换为仅添加以使代码更短一些。任何帮助都超过了感激！

package com.embah.Accgui;

import java.awt.*;

import javax.swing.*;

public class accCreator extends JFrame {

private String[] columnNames = {"Username", "Password", "Members", "World"};

private Object[][] data = {{"b", "b", "b", "b"},

                          { "e", "e", "e", "e"}};

    private JTable tbl_Accounts;

    private JScrollPane scrollPane;

    private JLabel lbl_Account = new JLabel();

    private JLabel lbl_Username = new JLabel();

    private JLabel lbl_Password = new JLabel();

    private JLabel lbl_Homeworld = new JLabel();

    private JButton btn_Select = new JButton();

    private JButton btn_Addacc = new JButton();

    private JButton btn_Delacc = new JButton();

    private JTextArea txt_Username = new JTextArea();

    private JTextArea txt_Password = new JTextArea();

    private JTextArea txt_Homeworld = new JTextArea();

    private JCheckBox cbox_Members = new JCheckBox();

    private JCheckBox cbox_RanWrld = new JCheckBox();

public accCreator() {

    setLayout(null);

    setupGUI();

    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

void setupGUI() {

    tbl_Accounts = new JTable(data, columnNames);

    tbl_Accounts.setLocation(5, 30);

    tbl_Accounts.setPreferredScrollableViewportSize(new Dimension(420, 250));

    tbl_Accounts.setFillsViewportHeight(true);

    tbl_Accounts.setVisible(true);

    add(tbl_Accounts);

    scrollPane = new JScrollPane(tbl_Accounts);

    add(scrollPane);

    lbl_Account.setLocation(4, 5);

    lbl_Account.setSize(100, 20);

    lbl_Account.setText("Select Account:");

    add(lbl_Account);

    lbl_Username.setLocation(5, 285);

    lbl_Username.setSize(70, 20);

    lbl_Username.setText("Username:");

    add(lbl_Username);

    lbl_Password.setLocation(5, 310);

    lbl_Password.setSize(70, 20);

    lbl_Password.setText("Password:");

    add(lbl_Password);

Answer 1

不能说谢谢你们，对不起，我这么固执，无法早日听你们说。我只是想制作一个不错的GUI，而我整天都在努力使它正常工作，我非常沮丧。Frak，您向我展示了setLayout（null）非常糟糕，不应该这样做。非常感谢您的投入和帮助！我非常感谢你们的帖子！