嵌套布局（FlowLayout 内的 GridBagLayout）

Question

如何使用此代码定位我的标签？似乎gridbaglayout在这里不起作用，尤其是gridbagconstraints。即使我更改了 gridx 和 gridy 值，标签也不会移动。

我需要把它做成 3 个偶数列，1 列 = 1 个面板

package nest;

import javax.swing.*;
import java.awt.*;

public class nested extends JFrame{

    public static void main(String[] args) {            
        JFrame f=new JFrame("Bio Data");
        JPanel p1=new JPanel(new GridBagLayout());
        JPanel p2=new JPanel(new GridBagLayout());
        //JPanel p3=new JPanel(new GridBagLayout());            
        GridBagConstraints c1=new GridBagConstraints();
        GridBagConstraints c2=new GridBagConstraints();            
        JLabel l1=new JLabel("aa");
        JLabel l2=new JLabel("bb");            
        c1.gridx=1;
        c1.gridy=1;
        p1.add(l1, c1);            
        c2.gridx=4;
        c2.gridy=4;
        p2.add(l2, c2);
        f.add(p1);
        f.add(p2);            
        f.setVisible(true);
        f.setSize(800,500);
        f.setResizable(false);
        f.setLayout(new FlowLayout());
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);            
    }
}

Answer 1

更改 gridx 和 gridy 不会更改标签的实际位置，而是更改标签显示的顺序/格式。如果您在 gridx 4 中有某些内容，但在 gridx 1,2 或 3 中没有任何内容，则该对象将是第一列。 此外，在每一列中放置一个新面板会很奇怪，因为您可以将内容放在 gridBagLayout 的不同行中。下面是一个带有三个不同标签列的 flowLayout 中的 gridBagLayout 的简短示例：

import java.awt.EventQueue;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.GridBagLayout;
import java.awt.GridBagConstraints;
import javax.swing.JLabel;
import java.awt.Insets;


public class nest extends JFrame {

    private JPanel contentPane;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    nest frame = new nest();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the frame.
     */
    public nest() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 450, 300);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);
        contentPane.setLayout(new GridLayout(0, 1, 0, 0));

        JPanel panel = new JPanel();
        contentPane.add(panel);
        panel.setLayout(new FlowLayout(FlowLayout.CENTER, 5, 5));

        JPanel panel_1 = new JPanel();
        panel.add(panel_1);
        GridBagLayout gbl_panel_1 = new GridBagLayout();
        gbl_panel_1.columnWidths = new int[]{0, 0, 27, 0};
        gbl_panel_1.rowHeights = new int[]{0, 16, 0};
        gbl_panel_1.columnWeights = new double[]{0.0, 0.0, 0.0, Double.MIN_VALUE};
        gbl_panel_1.rowWeights = new double[]{0.0, 0.0, Double.MIN_VALUE};
        panel_1.setLayout(gbl_panel_1);

        JLabel lblNewLabel_1 = new JLabel("New label");
        GridBagConstraints gbc_lblNewLabel_1 = new GridBagConstraints();
        gbc_lblNewLabel_1.insets = new Insets(0, 0, 5, 5);
        gbc_lblNewLabel_1.gridx = 0;
        gbc_lblNewLabel_1.gridy = 0;
        panel_1.add(lblNewLabel_1, gbc_lblNewLabel_1);

        JLabel lblNewLabel = new JLabel("New label");
        GridBagConstraints gbc_lblNewLabel = new GridBagConstraints();
        gbc_lblNewLabel.insets = new Insets(0, 0, 5, 5);
        gbc_lblNewLabel.gridx = 1;
        gbc_lblNewLabel.gridy = 0;
        panel_1.add(lblNewLabel, gbc_lblNewLabel);

        JLabel lblNewLabel_2 = new JLabel("New label");
        GridBagConstraints gbc_lblNewLabel_2 = new GridBagConstraints();
        gbc_lblNewLabel_2.insets = new Insets(0, 0, 5, 0);
        gbc_lblNewLabel_2.gridx = 2;
        gbc_lblNewLabel_2.gridy = 0;
        panel_1.add(lblNewLabel_2, gbc_lblNewLabel_2);

        JLabel lblLabel = new JLabel("New label");
        GridBagConstraints gbc_lblLabel = new GridBagConstraints();
        gbc_lblLabel.gridx = 2;
        gbc_lblLabel.gridy = 1;
        panel_1.add(lblLabel, gbc_lblLabel);
    }

}

我使用 Google WindowBuilder 创建了这个。请注意，您不一定需要设置 columnWidths、rowHeights、columnWeights 或 rowWeights（有时当您有动态内容时最好不要设置）。希望这会有所帮助。