java - 如何设置与按钮之间的间距不同的边距间隙？

Question

我有一个按钮面板，我希望按钮之间的间距为 25 像素，右边距为 5 像素，左边距为 5 像素(右侧的按钮位于窗口边框的 5 像素处)。

流式布局在各处设置了相同大小的间隙。 Gridlayout 允许这样做，但是所有按钮都具有相同的大小，这不是我想要的。我找到的唯一解决方案是将 Flow 布局设置为 hgap=0。然后我有一个emptyMargin，并且每个按钮之前都有一个刚性区域，但我认为这个解决方案是一个不好的做法。

最好的解决方案是什么？

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.FlowLayout;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class FlowLayoutDemo extends JFrame{
    FlowLayout experimentLayout = new FlowLayout(FlowLayout.LEFT, 25, 0);

    public FlowLayoutDemo(String name) {
        super(name);
    }

    public void addComponentsToPane(final Container pane) {
        final JPanel compsToExperiment = new JPanel();
        compsToExperiment.setLayout(experimentLayout);
        experimentLayout.setAlignment(FlowLayout.TRAILING);
        compsToExperiment.add(new JButton("Button 1"));
        compsToExperiment.add(new JButton("Button 2"));
        compsToExperiment.add(new JButton("Button 3"));
        compsToExperiment.add(new JButton("Long-Named Button 4"));
        compsToExperiment.add(new JButton("5"));
        pane.add(compsToExperiment, BorderLayout.CENTER);
    }

    private static void createAndShowGUI() {
        FlowLayoutDemo frame = new FlowLayoutDemo("FlowLayoutDemo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.addComponentsToPane(frame.getContentPane());
        frame.pack();
        frame.setVisible(true);
    }

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

Answer 1

考虑使用 GridBagLayout 来代替，它提供了更多的控制和自定义。

参见How to use GridBagLayout了解更多详情。

import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class Test {

    public static void main(String[] args) {
        new Test();
    }

    public Test() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        public TestPane() {
            setLayout(new GridBagLayout());
            GridBagConstraints gbc = new GridBagConstraints();
            gbc.gridy = 0;
            gbc.insets = new Insets(5, 5, 5, 25);
            gbc.fill = gbc.HORIZONTAL;
            gbc.weightx = 1;

            add(new JButton("Button 1"), gbc);
            gbc.insets = new Insets(5, 0, 5, 25);
            add(new JButton("Button 2"), gbc);
            add(new JButton("Button 3"), gbc);
            add(new JButton("Long-Named Button 4"), gbc);
            gbc.insets = new Insets(5, 0, 5, 5);
            add(new JButton("5"), gbc);
        }

    }

}

请注意，该示例强制按钮也占据所有可用空间。如果这不能满足您的具体需求，请尝试使用 fill 和 weightx 值