如何在Java Swing中創建響應式佈局

Question

我正在顯示一個揮杆JPanel中的鍵值對列表。該鍵顯示在JLabel中，並且該值顯示在JTextField中。面板上有足夠的空間顯示1或2列鍵值對，具體取決於父JFrame的大小。我想顯示2列鍵值對，除非面板太小。然後我想切換到一列。在沒有編寫我自己的自定義佈局管理器的情況下，這可能在Swing中嗎

將每個鍵值對放在它自己的面板上，並將面板添加到Flow Layout中將會做我想做的事情，除非標籤不會彼此對齊，並且文本字段不會彼此對齊，所以它會看起來很糟糕。有一個更好的方法嗎？

編輯：

這是它會是什麼樣子。如果面板足夠大，則顯示兩列。否則顯示一列。

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

你可以使用你的FlowLayout的想法，仍然使標籤/文本框的陣容。爲每個鍵/值面板添加一個支撐，該支撐是最長標籤的大小，以強制每個面板上的文本框向右移動相同的數量。類似：

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); 
    } 
}