我目前正在使用 Java Swing 构建 GUI。
我当前的代码产生了这个。 
Product List 的 JTextArea 使 GUI 看起来很尴尬，我怎样才能使 JTextArea 看起来像这样，它似乎有一个额外的行:
我使用的 GroupLayout 代码是:
gr.setVerticalGroup(gr.createSequentialGroup()
.addGroup(gr.createParallelGroup(GroupLayout.Alignment.BASELINE).addComponent(productName).addComponent(productText).addComponent(productList))
.addGroup(gr.createParallelGroup(GroupLayout.Alignment.BASELINE).addComponent(amount).addComponent(amountText).addComponent(prodScroll))
.addGroup(gr.createParallelGroup(GroupLayout.Alignment.BASELINE).addComponent(description).addComponent(desScroll))
.addGroup(gr.createParallelGroup(GroupLayout.Alignment.BASELINE).addComponent(addButton).addComponent(remButton)));
gr.setHorizontalGroup(gr.createSequentialGroup()
.addGroup(gr.createParallelGroup(GroupLayout.Alignment.LEADING).addComponent(productName).addComponent(amount).addComponent(description).addComponent(addButton))
.addGroup(gr.createParallelGroup(GroupLayout.Alignment.CENTER).addComponent(productText).addComponent(amountText).addComponent(desScroll).addComponent(remButton))
.addGroup(gr.createParallelGroup(GroupLayout.Alignment.CENTER).addComponent(productList).addComponent(prodScroll)));
最佳答案
我认为少数人会选择使用GridBagLayout .但是，我不喜欢它(与 GroupLayout 一样)，因为它“难以使用”。我使用嵌套面板代替各种 Layout Managers .只使用 BorderLayout 和 GridLayout 你可以实现类似下面的例子，它完全可以调整大小，强调“交互”组件(我的意思是，没有理由调整大小一个常量文本 JLabel，对吧？)
我没有故意添加任何评论，因此您可以在打开文档的同时试验常量(和布局约束)并查看它们存在的原因。
代码:
public class NestedLayoutManagersExample extends JFrame {
private static final long serialVersionUID = -7042997375941726246L;
private static final int labelsWidth = 80;
private static final int textFieldColumns = 15;
private static final int spaceBetweenAllComponents = 10;
public NestedLayoutManagersExample() {
super("test");
setDefaultCloseOperation(EXIT_ON_CLOSE);
JPanel contentPane = new JPanel(new GridLayout(1, 2, 50, 50));
contentPane.setBorder(BorderFactory.createEmptyBorder(spaceBetweenAllComponents, spaceBetweenAllComponents,
spaceBetweenAllComponents, spaceBetweenAllComponents));
setContentPane(contentPane);
add(createLeftPanel());
add(createRightPanel());
setLocationByPlatform(true);
pack();
}
private Component createRightPanel() {
JPanel mainPanel = new JPanel(new BorderLayout());
JLabel productListLabel = new JLabel("Product list");
mainPanel.add(productListLabel, BorderLayout.PAGE_START);
JList<String> productList = new JList<>();
DefaultListModel<String> listModel = new DefaultListModel<>();
Arrays.asList("Small Chair", "Big Chair", "Flying Chair").forEach(listModel::addElement);
productList.setModel(listModel);
JScrollPane listScrollPane = new JScrollPane(productList);
mainPanel.add(listScrollPane, BorderLayout.CENTER);
return mainPanel;
}
private Component createLeftPanel() {
JPanel mainPanel = new JPanel(new BorderLayout(spaceBetweenAllComponents, spaceBetweenAllComponents));
JPanel topPanel = new JPanel(new GridLayout(2, 1, spaceBetweenAllComponents, spaceBetweenAllComponents));
topPanel.add(createStraightPanel("Product Name"));
topPanel.add(createStraightPanel("Amount"));
mainPanel.add(topPanel, BorderLayout.PAGE_START);
JPanel centerPanel = new JPanel(new BorderLayout());
JLabel label = new JLabel("<html><p style='width:" + labelsWidth + "px';> Description");
label.setVerticalAlignment(JLabel.TOP);
centerPanel.add(label, BorderLayout.LINE_START);
centerPanel.add(createTextAreaPanel());
mainPanel.add(centerPanel, BorderLayout.CENTER);
return mainPanel;
}
private JPanel createTextAreaPanel() {
JPanel mainPanel = new JPanel(new BorderLayout(spaceBetweenAllComponents, spaceBetweenAllComponents));
JTextArea textArea = new JTextArea(1, textFieldColumns);
JScrollPane textAreaScrollPane = new JScrollPane(textArea);
mainPanel.add(textAreaScrollPane, BorderLayout.CENTER);
JPanel buttonsPanel = new JPanel(new BorderLayout());
JButton addButton = new JButton("Add");
buttonsPanel.add(addButton, BorderLayout.LINE_START);
JButton removeButton = new JButton("Remove");
buttonsPanel.add(removeButton, BorderLayout.LINE_END);
mainPanel.add(buttonsPanel, BorderLayout.PAGE_END);
return mainPanel;
}
private Component createStraightPanel(String labelText) {
JPanel mainPanel = new JPanel(new BorderLayout());
JLabel label = new JLabel("<html><p style='width:" + labelsWidth + "px';>" + labelText);
mainPanel.add(label, BorderLayout.LINE_START);
JTextField textField = new JTextField(textFieldColumns);
mainPanel.add(textField, BorderLayout.CENTER);
return mainPanel;
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> new NestedLayoutManagersExample().setVisible(true));
}
}
预览:
关于java - 在 JPanel 中对齐 JTextArea，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/59068440/