使用网格布局重复 WindowBuilder JLabel

Question

我想重复一个 JLabel "n" no。用户给出“n”的次数。 这个实现，使用 WindowBuilder 的 Grid 布局，不起作用，根本不打印。

我做错了什么？

JLabel lblNewLabel_1[]=new JLabel[20];
GridBagConstraints gbc_lblNewLabel_1[] = new GridBagConstraints[20];
for(int i=0;i<n;i++)
{
        lblNewLabel_1[i] = new JLabel("Table #");
        gbc_lblNewLabel_1[i].insets = new Insets(0, 0, 5, 5);
        gbc_lblNewLabel_1[i].gridx = 0;
        gbc_lblNewLabel_1[i].gridy = 4+i;
        frame.getContentPane().add(lblNewLabel_1[i], gbc_lblNewLabel_1[i]);
}

完整方法，我的内容窗格是网格布局。

private void initialize() {

        frame = new JFrame();
        frame.setBounds(100, 100, 507, 432);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        GridBagLayout gridBagLayout = new GridBagLayout();
        gridBagLayout.columnWidths = new int[]{57, 377, 0};
        gridBagLayout.rowHeights = new int[]{60, 37, 35, 20, 0, 0, 0, 0};
        gridBagLayout.columnWeights = new double[]{0.0, 0.0, Double.MIN_VALUE};
        gridBagLayout.rowWeights = new double[]{0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, Double.MIN_VALUE};
        frame.getContentPane().setLayout(gridBagLayout);

        textField = new JTextField();
        textField.setToolTipText("Max: 20");
        textField.setText("0");

        textField.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                if(arg0.getSource()==textField)
                    n = Integer.parseInt(arg0.getActionCommand());

            }
        });

        JLabel lblNewLabel = new JLabel("Enter The Number of Tables");
        lblNewLabel.setFont(new Font("Tahoma", Font.PLAIN, 30));
        GridBagConstraints gbc_lblNewLabel = new GridBagConstraints();
        gbc_lblNewLabel.insets = new Insets(0, 0, 5, 0);
        gbc_lblNewLabel.gridx = 1;
        gbc_lblNewLabel.gridy = 1;
        frame.getContentPane().add(lblNewLabel, gbc_lblNewLabel);
        GridBagConstraints gbc_textField = new GridBagConstraints();
        gbc_textField.insets = new Insets(0, 0, 5, 0);
        gbc_textField.fill = GridBagConstraints.HORIZONTAL;
        gbc_textField.gridx = 1;
        gbc_textField.gridy = 3;
        frame.getContentPane().add(textField, gbc_textField);
        textField.setColumns(10);

        GridBagConstraints gbc_lblNewLabel_1[] = new GridBagConstraints[20];
        for(int i=0;i<n;i++){
            lblNewLabel_1[i] = new JLabel("Table #");
            gbc_lblNewLabel_1[i].insets = new Insets(0, 0, 5, 5);
            gbc_lblNewLabel_1[i].gridx = 0;
            gbc_lblNewLabel_1[i].gridy = 4+i;
            frame.getContentPane().add(lblNewLabel_1[i], gbc_lblNewLabel_1[i]);
        }
    }

Answer 1

JFrame 的默认布局是BorderLayout。

如果要使用GridBagLayout，则需要将内容窗格的布局设置为使用 GridBagLayout。

我建议您阅读 How to Use GridBagLayout 上的 Swing 教程中的部分以获得更多解释和工作示例。

如果您想使用GridLayout，那么您还需要将内容窗格的布局管理器设置为 GridLayout，并且您不使用任何约束。再次阅读示例教程。