使用GridBagLayout（Java）构建GUI

Question

我正在尝试使用GridBagLayout为一个小型Java游戏构建一个GUI。最后它应该是这样的：

这是我的代码：

    private GridBagConstraints c;

    ...

    c.gridx = 1;
    c.gridy = 0;
    c.weightx = 0;
    add(playButton, c);

    c.gridx = 1;
    c.gridy = 1;
    c.weightx = 0;
    add(optionsButton, c);

    c.gridx = 1;
    c.gridy = 2;
    c.weightx = 0;
    add(manualButton, c);

    c.gridx = 1;
    c.gridy = 3;
    c.weightx = 0;
    add(exitButton, c); 

    c.gridx = 0;
    c.gridy = 4;
    c.weightx = 1;      
    c.anchor = GridBagConstraints.SOUTHWEST;
    add(creditsButton, c);

    c.gridx = 2;
    c.gridy = 4;
    c.weightx = 1;
    c.anchor = GridBagConstraints.SOUTHEAST;
    add(legalNoticeButton, c);

目前它看起来像这样：

我的问题是我可以将两个按钮设置在底部而不将其他四个底部设置到顶部？

Answer 1

这样的事情或多或少是@Gilbert Le Blanc解释的（有微小的差别）：

基本上使用另一个面板将两个按钮向南移动并将它们分散到WEST和EAST：

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;

import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class TestGridBagLayout {

    protected void initUI() {
        JFrame frame = new JFrame("test");
        final JPanel centerPanel = new JPanel();
        centerPanel.setLayout(new GridBagLayout());
        JButton playButton = new JButton("Play");
        JButton optionsButton = new JButton("Options");
        JButton manualButton = new JButton("Manual");
        JButton exitButton = new JButton("Exit");
        JButton creditsButton = new JButton("Credits");
        JButton legalNoticeButton = new JButton("Legal");
        GridBagConstraints c = new GridBagConstraints();
        c.gridwidth = GridBagConstraints.REMAINDER;
        centerPanel.add(playButton, c);
        centerPanel.add(optionsButton, c);
        centerPanel.add(manualButton, c);
        centerPanel.add(exitButton, c);

        JPanel bottomPanel = new JPanel(new BorderLayout());
        bottomPanel.add(creditsButton, BorderLayout.WEST);
        // Filler component that avoids having the bottom panel too small
        bottomPanel.add(new JComponent() {
            @Override
            public Dimension getPreferredSize() {
                return new Dimension(centerPanel.getPreferredSize().width, 0);
            }
        });
        bottomPanel.add(legalNoticeButton, BorderLayout.EAST);
        frame.add(centerPanel);
        frame.add(bottomPanel, BorderLayout.SOUTH);
        frame.pack();
        frame.setMinimumSize(frame.getPreferredSize());
        frame.setVisible(true);
    }

    public static void main(String[] args) throws ClassNotFoundException, InstantiationException, IllegalAccessException,
            UnsupportedLookAndFeelException {
        UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                new TestGridBagLayout().initUI();
            }
        });
    }
}