网格包布局未按我想要的方式显示

Question

所以我有 6 个面板，所有面板都使用网格布局。 我用gridbaglayout把它们放在一起，这是我想要的设计

结果一团糟 “第二个”面板变得离右边更远了 第三个面板向左挤压了很多，这是一场灾难。 这是我的网格包布局代码

    c.gridx = 0; c.gridy = 0;
    add (first,c); 

    c.gridx = 2; //so that the second panel starts from the center and is divided evenly with the first panel
    add(second,c);

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

    c.gridx = 1; 
    add(fourth,c);

    c.gridx = 2;
    add(fifth,c);

    c.gridx = 3;
    add(sixth,c);

感谢任何帮助。

Answer 1

在您编写c.gridx = 0 and c.gridy = 0 时，您忘记指定您希望此JPanel 占用多少列。为了指定这一点，您应该使用c.gridwidth = 2，它告诉布局这个JPanel 需要两列的空间。

要得到这样的输出：

这是一个小的工作示例：

import java.awt.*;
import javax.swing.*;
// http://stackoverflow.com/questions/10968853/two-jpanels-in-jframe-one-under-other
public class GridBagLayoutExample
{
    // http://stackoverflow.com/questions/10977017/grid-bag-layout-not-displaying-the-way-i-want
    private void displayGUI()
    {
        JFrame frame = new JFrame("GridBagLayout Example");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JPanel contentPane = new JPanel();
        contentPane.setLayout(new GridBagLayout());

        GridBagConstraints gbc = new GridBagConstraints();
        gbc.anchor = GridBagConstraints.FIRST_LINE_START;
        gbc.fill = GridBagConstraints.BOTH;
        gbc.gridx = 0;
        gbc.gridy = 0;
        gbc.gridwidth = 2;
        gbc.weightx = 0.5;
        gbc.weighty = 0.2;

        JPanel topLeftPanel = new JPanel();
        topLeftPanel.setOpaque(true);
        topLeftPanel.setBackground(Color.DARK_GRAY);
        contentPane.add(topLeftPanel, gbc);

        gbc.gridx = 2;

        JPanel topRightPanel = new JPanel();
        topRightPanel.setOpaque(true);  
        topRightPanel.setBackground(Color.BLUE);
        contentPane.add(topRightPanel, gbc);

        gbc.gridwidth = 1;
        gbc.gridx = 0;
        gbc.gridy = 1;
        gbc.weightx = 0.25;
        gbc.weighty = 0.8;

        JPanel firstPanel = new JPanel();
        firstPanel.setOpaque(true);
        firstPanel.setBackground(Color.RED);
        contentPane.add(firstPanel, gbc);

        gbc.gridx = 1;

        JPanel secondPanel = new JPanel();
        secondPanel.setOpaque(true);
        secondPanel.setBackground(Color.GREEN.darker());
        contentPane.add(secondPanel, gbc);

        gbc.gridx = 2;

        JPanel thirdPanel = new JPanel();
        thirdPanel.setOpaque(true);
        thirdPanel.setBackground(Color.WHITE);
        contentPane.add(thirdPanel, gbc);

        gbc.gridx = 3;

        JPanel fourthPanel = new JPanel();
        fourthPanel.setOpaque(true);
        fourthPanel.setBackground(Color.MAGENTA);
        contentPane.add(fourthPanel, gbc);

        frame.setContentPane(contentPane);
        frame.setSize(200, 300);
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }

    public static void main(String... args)
    {
        SwingUtilities.invokeLater(new Runnable()
        {
            public void run()
            {
                new GridBagLayoutExample().displayGUI();
            }           
        });
    }
}

Answer 2

这是（另一种）替代嵌套布局。面板 3 到 6 将获得额外的高度，额外的宽度将平均分配给所有 6 个面板。

import java.awt.*;
import javax.swing.*;
import javax.swing.border.LineBorder;
import javax.swing.border.TitledBorder;

public class SixPanelNested {

    SixPanelNested() {
        JPanel gui = new JPanel(new BorderLayout());
        gui.setBorder(new TitledBorder("BorderLayout()"));

        JPanel north = new JPanel(new GridLayout(1,0));
        north.setBorder(new TitledBorder("GridLayout(1,0)"));
        gui.add(north, BorderLayout.NORTH);
        for (int ii=1; ii<3; ii++) {
            JLabel l = new JLabel("Panel " + ii);
            l.setBorder(new LineBorder(Color.BLACK));
            north.add(l);
        }

        JPanel south = new JPanel(new GridLayout(1,0));
        south.setBorder(new TitledBorder("GridLayout(1,0)"));
        gui.add(south);
        for (int ii=3; ii<7; ii++) {
            JLabel l = new JLabel("Panel " + ii);
            l.setBorder(new LineBorder(Color.BLACK));
            south.add(l);
        }

        JOptionPane.showMessageDialog(null, gui);
    }

    public static void main(String[] args) throws Exception {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                new SixPanelNested();
            }
        });
    }
}

Answer 3

我对@9​​87654321@ 不够熟悉，无法快速发现您可以改进代码以解决此问题。但是另一种方法可能是可能的，使用嵌套的BorderLayouts。

面板“第一”、“第三”和“第四”可以放置在一个JPanelA内，BorderLayout 分别位于NORTH、WEST 和EAST。 JPanel B 中的“第二”、“第五”和“第六”面板也可以这样做。

然后你将这两个面板（A 和 B）分组到另一个面板中，BorderLayout 在 WEST 和 EAST 中

Answer 4

添加这个：

c.gridwidth = 2;

在添加 FIRST 和 SECOND 面板之前，在添加其他面板之前将 gridwidth 设置回 1。 或者，您可以按照上面的建议将它们进一步分开。您可以为每一行使用两个 FlowLayout，并将这两个添加到另一个具有 NORTH/SOUTH 的 BorderLayout 的面板。