java - JFrame GridBagLayout 组件定位

Question

因此，我使用的是空布局，但被告知这是一个糟糕的主意，因此决定使用 GridBagLayout，因为它被认为是最容易定制的。我在定位我的组件时遇到了问题，我真的很困惑如何在屏幕的顶部中间放置一个标签，在中间放置我的表格，在右下角放置我的登录按钮。有谁知道如何做到这一点？

这是我的代码:

import javafx.geometry.HorizontalDirection;

import javax.swing.*;
import javax.swing.table.DefaultTableModel;
import java.awt.*;
import java.awt.event.*;

public class Main
{

    JFrame window = new JFrame("PE Fixture");   //JFrame variables

    JPanel container = new JPanel();
    JPanel guestFixturesPanel = new JPanel();
    JPanel loginPanel = new JPanel();
    JPanel adminFixturesPanel = new JPanel();
    JPanel createPanel = new JPanel();

    String[] columns = {"Sport", "Location", "Date", "Result"};
    String[][] data = {{"Football", "AQA Highschool", "12.11.13", "5 - 0"},
            {"Tennis", "Wembley", "26.11.14.", "TBC"}};


    CardLayout cardLayout = new CardLayout();
    GridBagConstraints c = new GridBagConstraints();

    public Main()
    {

        container.setLayout(cardLayout);

        guestFixturesPanel.setLayout(new GridBagLayout());        //GUEST FIXTURES PANEL COMPONENTS

        JButton loginButton = new JButton("Login");
        c.gridx = 0;
        c.gridy = 2;
        c.insets = new Insets(0, 0, 10, 0);
        guestFixturesPanel.add(loginButton, c);
        JTable fixturesTable = new JTable(data, columns)
        {
            public boolean isCellEditable(int data, int columns)
            {
                return false;
            }
        };
        fixturesTable.setPreferredScrollableViewportSize(new Dimension(500, 300));
        fixturesTable.setFillsViewportHeight(true);
        JScrollPane scrollTable = new JScrollPane(fixturesTable);
        c.gridx = 0;
        c.gridy = 0;
        c.ipady = 700;
        c.ipadx = 400;
        guestFixturesPanel.add(scrollTable, c);
        JLabel fixturesLabel = new JLabel("FIXTURES");
        fixturesLabel.setFont(new Font("TimesRoman", Font.PLAIN, 50));
        fixturesLabel.setForeground(Color.WHITE);
        c.gridx = 0;
        c.gridy = 0;
        guestFixturesPanel.add(fixturesLabel, c);

        container.add(guestFixturesPanel, "2");         //LABELS EACH COMPONENT WITH A NUMBER
        container.add(loginPanel, "3");
        container.add(adminFixturesPanel, "4");
        container.add(createPanel, "5");

        guestFixturesPanel.setBackground(Color.DARK_GRAY);      //Colours each panel
        loginPanel.setBackground(Color.DARK_GRAY);
        adminFixturesPanel.setBackground(Color.DARK_GRAY);
        createPanel.setBackground(Color.DARK_GRAY);
        cardLayout.show(container, "1");

        window.add(container);          //Creates the frame of the program.
        window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        window.setSize(500, 860);
        window.setResizable(false);
        window.setVisible(true);

    }

    public static void main(String[] args)
    {

        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                new Main();
            }
        });

    }
}

编辑:

import javax.swing.*;
import javax.swing.table.DefaultTableModel;
import java.awt.*;
import java.awt.event.*;

    public class Main
    {
        String[] columns = {"Sport", "Location", "Date", "Result"};
        String[][] data = {{"Football", "AQA Highschool", "12.11.13", "5 - 0"},
                {"Tennis", "Wembley", "26.11.14.", "TBC"}};

        private void createAndShowGUI()
        {
            CardLayout layout = new CardLayout();

            JPanel guestCard = new JPanel(layout);
            JPanel guestTitle = new JPanel(new FlowLayout(FlowLayout.CENTER));               //GUEST TOP PANEL
            JLabel fixturesLabel = new JLabel("FIXTURES");
            fixturesLabel.setFont(new Font("TimesRoman", Font.PLAIN, 50));
            fixturesLabel.setForeground(Color.WHITE);
            guestTitle.add(fixturesLabel);
            JTable fixturesTable = new JTable(data, columns)                                 //GUEST MID PANEL
            {
                public boolean isCellEditable(int data, int columns)
                {
                    return false;
                }
            };
            fixturesTable.setPreferredScrollableViewportSize(new Dimension(350, 450));
            fixturesTable.setFillsViewportHeight(true);
            JScrollPane scrollTable = new JScrollPane(fixturesTable);
            JPanel guestBot = new JPanel(new FlowLayout(FlowLayout.RIGHT));                  //GUEST BOT PANEL
            JButton loginButtonGuest = new JButton("Login");
            guestBot.add(loginButtonGuest);



            JPanel loginCard = new JPanel(layout);                                           //LOGIN TOP PANEL
            JPanel loginTitle = new JPanel(new FlowLayout(FlowLayout.CENTER));
            JLabel loginLabel = new JLabel("LOGIN");
            loginLabel.setFont(new Font("TimesRoman", Font.PLAIN, 50));
            loginLabel.setForeground(Color.WHITE);
            loginTitle.add(loginLabel);

            JPanel container = new JPanel(new BorderLayout(8,8));                           //ADDS CARDS TO CONTAINER
            container.add(guestCard, "2");
            container.add(loginCard, "3");

            guestCard.add(guestTitle, BorderLayout.NORTH);                                  //ADDS COMPONENTS TO CARDS
            guestCard.add(scrollTable, BorderLayout.CENTER);
            guestCard.add(guestBot, BorderLayout.SOUTH);
            loginCard.add(loginTitle, BorderLayout.NORTH);

            container.setBackground(Color.DARK_GRAY);                                       //COLOURS CARDS
            guestTitle.setBackground(Color.DARK_GRAY);
            scrollTable.setBackground(Color.DARK_GRAY);
            guestBot.setBackground(Color.DARK_GRAY);

            layout.show(container, "1");

            JFrame window = new JFrame("PE Fixtures");                                      //CREATES WINDOW
            window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            window.getContentPane().add(container);
            window.setSize(400, 700);
            window.setLocationRelativeTo(null);
            window.setResizable(false);
            window.setVisible(true);

        }

        public static void main(String[] args) {
            SwingUtilities.invokeLater(new Runnable() {
                @Override
                public void run() {
                    new Main().createAndShowGUI();
                }
            });
        }
    }

错误:

"C:\Program Files\Java\jdk1.7.0_51\bin\java" -Didea.launcher.port=7533 "-Didea.launcher.bin.path=C:\Program Files (x86)\JetBrains\IntelliJ IDEA Community Edition 13.0.2\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.7.0_51\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.7.0_51\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.7.0_51\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.7.0_51\jre\lib\jce.jar;C:\Program Files\Java\jdk1.7.0_51\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.7.0_51\jre\lib\jfxrt.jar;C:\Program Files\Java\jdk1.7.0_51\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.7.0_51\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.7.0_51\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.7.0_51\jre\lib\resources.jar;C:\Program Files\Java\jdk1.7.0_51\jre\lib\rt.jar;C:\Program Files\Java\jdk1.7.0_51\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.7.0_51\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.7.0_51\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.7.0_51\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.7.0_51\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.7.0_51\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.7.0_51\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.7.0_51\jre\lib\ext\zipfs.jar;C:\Users\Harry\Desktop\Computer Science Projects\PE Fixtures v2.0\out\production\PE Fixtures v2.0;C:\Program Files (x86)\JetBrains\IntelliJ IDEA Community Edition 13.0.2\lib\idea_rt.jar" com.intellij.rt.execution.application.AppMain Main
Exception in thread "AWT-EventQueue-0" java.lang.IllegalArgumentException: cannot add to layout: unknown constraint: 2
    at java.awt.BorderLayout.addLayoutComponent(BorderLayout.java:463)
    at java.awt.BorderLayout.addLayoutComponent(BorderLayout.java:424)
    at java.awt.Container.addImpl(Container.java:1120)
    at java.awt.Container.add(Container.java:966)
    at Main.createAndShowGUI(Main.java:48)
    at Main.access$000(Main.java:8)
    at Main$2.run(Main.java:77)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:733)
    at java.awt.EventQueue.access$200(EventQueue.java:103)
    at java.awt.EventQueue$3.run(EventQueue.java:694)
    at java.awt.EventQueue$3.run(EventQueue.java:692)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:703)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)

Answer 1

I am really confused as to how I can get a label to the top middle of the screen, my table in the middle, and my login button to the bottom right.

如你所见GridBagLayout不是最简单的布局管理器(麻烦太多，功能也不多)。要布置这么少量的组件，我建议您使用 Nested Layout方法:

• 使用BorderLayout布置“主要”面板组件(标签、表格和按钮)。
• 使用FlowLayout将标签置于顶部面板的中央，并将按钮放在底部面板的右侧。

例子

import java.awt.BorderLayout;
import java.awt.FlowLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.table.DefaultTableModel;

public class Demo {

    private void createAndShowGUI() {

        JLabel label = new JLabel("Title");
        label.setFont(label.getFont().deriveFont(Font.BOLD | Font.ITALIC, 18));
        JPanel topPanel = new JPanel(new FlowLayout(FlowLayout.CENTER));
        topPanel.add(label);

        DefaultTableModel model = new DefaultTableModel(new Object[]{"Column # 1", "Column # 2"}, 0);
        model.addRow(new Object[]{"Property # 1", "Value # 1"});
        model.addRow(new Object[]{"Property # 2", "Value # 2"});
        model.addRow(new Object[]{"Property # 3", "Value # 3"});

        JTable table = new JTable(model);
        JScrollPane scrollPane = new JScrollPane(table);            

        JButton button = new JButton("Log In");
        JPanel bottomPanel = new JPanel(new FlowLayout(FlowLayout.RIGHT));
        bottomPanel.add(button);

        JPanel content = new JPanel(new BorderLayout(8, 8));
        content.add(topPanel, BorderLayout.NORTH);
        content.add(scrollPane, BorderLayout.CENTER);
        content.add(bottomPanel, BorderLayout.SOUTH);

        JFrame frame = new JFrame("Demo");
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        frame.getContentPane().add(content);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {                
                new Demo().createAndShowGUI();
            }
        });
    }    
}

截图

---

此外

对于更复杂的 GUI 设计，您可能想尝试 this answer 中建议的这些第三方布局管理器之一。 :

• MigLayout
• DesignGridLayout
• FormLayout