我如何在Java Swing中创建响应式布局

Question

我在swing JPanel中显示一个键值对列表.密钥显示在JLabel中,值显示在JTextField中.面板上有足够的空间来显示1或2列键值对,具体取决于父JFrame的大小.除非面板太小,否则我想显示2列键值对.然后我想切换到一列.这可以在Swing中编写我自己的自定义布局管理器吗？

将每个键值对放在它自己的面板上并将面板添加到Flow Layout会做我想做的事情,除了标签不会彼此对齐并且文本字段不会彼此对齐因此看起来很糟糕.有一个更好的方法吗？

编辑:

这是它的样子.如果面板足够大,则显示两列.否则显示一列.

2列:

   Some Key _______________                Key 2 ________________ 
Another Key _______________      Yet Another Key ________________
      Key 5 _______________                Key 6 ________________

1列

       Some Key _______________                
          Key 2 _______________ 
    Another Key _______________      
Yet Another Key _______________
          Key 5 _______________                
          Key 6 ________________

Answer 1

您可以使用您的 FlowLayout 想法，并且仍然使标签/文本字段排列。向每个键/值面板添加一个支柱，该支柱的大小与最长标签的大小相同，以强制每个面板上的文本字段向右伸出相同的量。就像是：

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

public class Test implements Runnable
{
  private String[] keys = {"One", "Twoooooo", "Three", "Four",
                           "Five", "Six", "Seven", "Eight",
                           "Nine", "Ten", "Eleven", "Twelve"};
  private String[] values = {"Apple", "Boy", "Cat", "Denmark",
                             "Elephant", "Foo", "Hello", "Igloo",
                             "Jug", "Kangaroo", "Lip", "Now"};

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

  public void run()
  {
    JPanel panel = new JPanel(new FlowLayout());
    GridBagConstraints gbc;
    JTextField textField = null;
    int maxWidth = 0;
    JLabel[] labels = new JLabel[keys.length];

    for (int i = 0; i < keys.length; i++)
    {
      labels[i] = new JLabel(keys[i]);
      maxWidth = Math.max(labels[i].getPreferredSize().width, maxWidth);
    }

    JPanel[] panels = new JPanel[keys.length];

    for (int i = 0; i < keys.length; i++)
    {
      panels[i] = new JPanel(new GridBagLayout());

      gbc = new GridBagConstraints();
      gbc.gridx = 0;
      gbc.gridy = 0;
      gbc.anchor = GridBagConstraints.EAST;
      gbc.insets = new Insets(1,1,1,1);
      panels[i].add(Box.createHorizontalStrut(maxWidth), gbc);

      gbc.gridy = 1;
      panels[i].add(labels[i], gbc);

      textField = new JTextField(10);
      textField.setText(values[i]);
      gbc.gridx = 1;
      panels[i].add(textField, gbc);

      panel.add(panels[i]);
    }

    JFrame frame = new JFrame("Test");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.getContentPane().add(panel);
    frame.setSize(240, 400);
    frame.setLocationRelativeTo(null);
    frame.setVisible(true);
  }
}