java - 如何增加Tab中JTextField的宽度？

Question

在Food Tab中，我想实现这个

但我只能得到这个

如何增加 Food Tab 中 JTextField 的宽度？下面是我的代码

 public class FoodOrdering {
        static private JFrame frame;
        static private JTextField textField;
        static private GridBagConstraints gbc;
        static private JLabel[] foodLabel;
        static private JLabel[] labels;
        static private JTextField[] qtyField;
        static private JLabel[] foodImage;
        static private File[] file;
        private static final int ELEMENTS = 9;
        /**
         * Launch the application.
         */
        public static void main(String[] args) {
            EventQueue.invokeLater(new Runnable() {
                public void run() {
                    try {
                        FoodOrdering window = new FoodOrdering();
                        window.frame.setVisible(true);
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            });
        }
        /**
         * Create the application.
         * 
         * @throws IOException
         */
        public FoodOrdering() throws IOException {
            initialize();
        }
        /**
         * Initialize the contents of the frame.
         * 
         * @throws IOException
         */
            static void initialize() throws IOException {
            frame = new JFrame();
            frame.setBounds(100, 100, 700, 550);
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            frame.getContentPane().setLayout(null);
            frame.setLocationRelativeTo(null);
            JLabel lblFoodOrdered = new JLabel("Food Ordered");
            lblFoodOrdered.setBounds(529, 11, 81, 14);
            frame.getContentPane().add(lblFoodOrdered);
            TextArea textArea = new TextArea();
            textArea.setBounds(462, 31, 199, 275);
            frame.getContentPane().add(textArea);
            JLabel lblTotal = new JLabel("Total  : ");
            lblTotal.setBounds(519, 315, 46, 14);
            frame.getContentPane().add(lblTotal);
            textField = new JTextField();
            textField.setBounds(575, 312, 86, 20);
            frame.getContentPane().add(textField);
            textField.setColumns(10);
            JButton btnOrder = new JButton("Order");
            btnOrder.setBounds(521, 352, 89, 23);
            frame.getContentPane().add(btnOrder);
            JTabbedPane tabbedPane = new JTabbedPane(JTabbedPane.TOP);
            addIt(tabbedPane, "Foods");
            addIt1(tabbedPane, "Drinks");
            addIt1(tabbedPane, "Desserts");
            tabbedPane.setBounds(23, 11, 400, 450);
            frame.getContentPane().add(tabbedPane);
            frame.setVisible(true);
        }
        static void addIt1(JTabbedPane tabbedPane, String text) {
            JLabel label = new JLabel(text);
            JButton button = new JButton(text);
            JPanel panel = new JPanel();
            panel.add(label);
            panel.add(button);
            tabbedPane.addTab(text, panel);
        }
        static void addIt(JTabbedPane tabbedPane, String text) throws IOException {
            JPanel panel = new JPanel(new GridBagLayout());
            gbc = new GridBagConstraints();
            gbc.insets = new Insets(1, 1, 1, 1);
            foodImage = new JLabel[ELEMENTS];
            foodLabel = new JLabel[ELEMENTS];
            labels = new JLabel[ELEMENTS];
            qtyField = new JTextField[ELEMENTS];
            file = new File[ELEMENTS];
            try {
                file[0] = new File("C:\\Users\\tony\\Desktop\\MedSalad.png");
                file[1] = new File("C:\\Users\\tony\\Desktop\\JapanesePanNoodles.png");
                file[2] = new File("C:\\Users\\tony\\Desktop\\Spaghetti.png");
                file[3] = new File("C:\\Users\\tony\\Desktop\\PadThai.png");
                file[4] = new File("C:\\Users\\tony\\Desktop\\RamenNoodles.png");
                file[5] = new File("C:\\Users\\tony\\Desktop\\SpaghettiAndMeatBalls.png");
                file[6] = new File("C:\\Users\\tony\\Desktop\\chickenRice.jpg");
                file[7] = new File("C:\\Users\\tony\\Desktop\\thaiFood.jpeg");
                file[8] = new File("C:\\Users\\tony\\Desktop\\vietnamFood.jpg");
                foodLabel[0] = new JLabel("Salad");
                foodLabel[1] = new JLabel("Japanese Noodles");
                foodLabel[2] = new JLabel("Spaghetti");
                foodLabel[3] = new JLabel("Spaghetti Meat Balls");
                foodLabel[4] = new JLabel("Noodles");
                foodLabel[5] = new JLabel("Kids Spaghetti");
                foodLabel[6] = new JLabel("Chicken Rice");
                foodLabel[7] = new JLabel("Thai Food");
                foodLabel[8] = new JLabel("Vietnam Food");
            } catch (Exception e) {
                e.printStackTrace();
            }
            for (int i = 0; i < ELEMENTS; i++) {
                Image image = ImageIO.read(file[i]);
                Image imageScaled = image.getScaledInstance(80, 95, Image.SCALE_SMOOTH);
                ImageIcon imageIcon = new ImageIcon(imageScaled);
                qtyField[i] = new JTextField(3);
                foodImage[i] = new JLabel(imageIcon);
            }
            gbc.gridx = 0;
            for (int i = 0; i < ELEMENTS; i++) {
                if (i % 3 == 0) {
                    gbc.gridy += 2;
                    gbc.gridx = 0;
                }
                panel.add(foodImage[i], gbc);
                gbc.gridy++;
                panel.add(foodLabel[i], gbc);
                gbc.gridy--;
                gbc.gridx++;
                panel.add(qtyField[i], gbc);
                gbc.gridx++;
                tabbedPane.addTab(text, panel);
            }
        }
        public void setVisible(boolean b) throws IOException {
        }
    }

Answer 1

由于 a very old "bug"，JTextfield 对象非常窄在 GridBagLayout 中，这导致它忽略其内容的首选大小。

有几种可能的方法来解决这个错误:

1. 按照链接中的说明创建一个名为 PreferredGridBagLayout 的类，并使用它代替 GridBagLayout。
2. 使用 qtyField[i].setMinimumSize(qtyField[i].getPreferredSize()) 设置每个 qtyField 实例的最小大小。
3. 创建 JTextField 的子类，覆盖方法 getMinimumSize() 以返回与 getPreferredSize() 相同的值，或其他一些合理的最小值大小。

因为这个问题在使用 GridBagLayout 时很常见，从长远来看，解决方案 #1 是最简单的。

之后，您需要使 tabbedPane 对象更宽一些，或者切换到主面板中的布局管理器，自动确定选项卡式 Pane 的大小。

您的代码中有很多地方可以改进。在 Swing 中创建良好的布局并不容易，您需要做更多的工作才能创建漂亮的布局。但这将解决您折叠文本字段的问题。