防止BoxLayout扩展子级

编辑Kleopatra: import javax.swing.*;import java.awt.*;public class TextAreaTester { public static void main(String[] args) { new TextAreaTester(); } public TextAreaTester() { JFrame frame = new JFrame(); JPanel panel = new JPanel(); panel.setLayout(new BoxLayout(panel, BoxLayout.PAGE_AXIS)); // panel.setPreferredSize(new Dimension(100,400)); for (int i = 0; i < 3; i++) { JPanel item = new JPanel(new BorderLayout()); // item.setLayout(new BoxLayout(item,BoxLayout.LINE_AXIS)); JTextArea textarea = new JTextArea( "this is a line of text I want to wrap if necessary", 3, 35); textarea.setWrapStyleWord(true); textarea.setLineWrap(true); // textarea.setMaximumSize(textarea.getPreferredSize()); // item.setMaximumSize( item.getPreferredSize() ); item.add(new JScrollPane(textarea), BorderLayout.NORTH); panel.add(item); } panel.add(Box.createGlue()); JPanel mainPanel = new JPanel(new BorderLayout()) { private final int prefW = 100; private final int prefH = 400; @Override public Dimension getPreferredSize() { return new Dimension(prefW, prefH); } }; // mainPanel.setPreferredSize(new Dimension(100, 400)); mainPanel.add(panel, BorderLayout.PAGE_START); frame.add(mainPanel); frame.setVisible(true); // frame.getContentPane().add(jp); frame.pack(); }}I want to stack some JComponents vertically inside a JPanel so they stack at the top and any extra space is at the bottom. I'm using a BoxLayout. The components will each contain a JTextArea that should allow the text to wrap if necessary. So, basically, I want the height of each of these components to be the minimum necessary for displaying the (possibly wrapped) text.Here's a contained code example of what I'm doing:import javax.swing.*;import java.awt.*;public class TextAreaTester { public static void main(String[] args){ new TextAreaTester(); } public TextAreaTester(){ JFrame frame = new JFrame(); JPanel panel = new JPanel(); panel.setLayout(new BoxLayout(panel,BoxLayout.PAGE_AXIS)); panel.setPreferredSize(new Dimension(100,400)); for(int i = 0; i<3; i++){ JPanel item = new JPanel(new BorderLayout()); JTextArea textarea = new JTextArea("this is a line of text I want to wrap if necessary"); textarea.setWrapStyleWord(true); textarea.setLineWrap(true); textarea.setMaximumSize( textarea.getPreferredSize() ); item.add(textarea,BorderLayout.NORTH); panel.add(item); } panel.add(Box.createGlue()); frame.add(panel); frame.setVisible(true); frame.pack(); }}The child JPanels are expanding to fill the vertical space. I tried using glue because I thought that's what glue was for, but it seems to do nothing at all. Any help?Note: I have found questions that look almost identical, but none with answers I can apply. 解决方案 One solution: nest JPanels with the outer JPanel using Borderlayout and adding the BoxLayout using JPanel to this one BorderLayout.NORTH, also known as BorderLayout.PAGE_START:Edit for Kleopatra: import javax.swing.*;import java.awt.*;public class TextAreaTester { public static void main(String[] args) { new TextAreaTester(); } public TextAreaTester() { JFrame frame = new JFrame(); JPanel panel = new JPanel(); panel.setLayout(new BoxLayout(panel, BoxLayout.PAGE_AXIS)); // panel.setPreferredSize(new Dimension(100,400)); for (int i = 0; i < 3; i++) { JPanel item = new JPanel(new BorderLayout()); // item.setLayout(new BoxLayout(item,BoxLayout.LINE_AXIS)); JTextArea textarea = new JTextArea( "this is a line of text I want to wrap if necessary", 3, 35); textarea.setWrapStyleWord(true); textarea.setLineWrap(true); // textarea.setMaximumSize(textarea.getPreferredSize()); // item.setMaximumSize( item.getPreferredSize() ); item.add(new JScrollPane(textarea), BorderLayout.NORTH); panel.add(item); } panel.add(Box.createGlue()); JPanel mainPanel = new JPanel(new BorderLayout()) { private final int prefW = 100; private final int prefH = 400; @Override public Dimension getPreferredSize() { return new Dimension(prefW, prefH); } }; // mainPanel.setPreferredSize(new Dimension(100, 400)); mainPanel.add(panel, BorderLayout.PAGE_START); frame.add(mainPanel); frame.setVisible(true); // frame.getContentPane().add(jp); frame.pack(); }} 这篇关于防止BoxLayout扩展子级的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 上岸，阿里云！