Question

在调用Component和GroupLayout之后，setHorizontalGroup()可以setVerticalGroup()动态添加GroupLayout组，而无需重置布局？我正在GUI上创建一个项目，帮助学生找到最好的方法来整理他们的每周课程安排。这涉及输入关于类时间等的信息，用于未知数量的类。当然，我不能只是为用户添加任意数量的表单来将信息输入并说“没有人考虑超过这个数量的类”＃34;所以用户需要能够自己添加新表格。我可以创建表单，但我无法找到任何方法将其成功添加到窗口中的setHorizontalGroup(...)，而无需重新调用setVerticalGroup(...)或Group之前的private static void createAndShowGUI() { //Create window and assign an empty GroupLayout to it JFrame frame = new JFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); GroupLayout layout = new GroupLayout(frame.getContentPane()); frame.getContentPane().setLayout(layout); /*WeekPanel extends JPanel, and is the "form" the user enters data into. In essence, it's a JPanel with a series of JTextFields.*/ WeekPanel panel1 = new WeekPanel(); WeekPanel panel2 = new WeekPanel(); //The layout code below places two WeekPanels in the window, one on top of the other layout.setHorizontalGroup(layout.createSequentialGroup() .addGroup(layout.createParallelGroup() .addComponent(panel1) .addComponent(panel2))); layout.setVerticalGroup(layout.createSequentialGroup() .addComponent(panel1) .addComponent(panel2)); /*I would like to add a component to the layout here as proof of concept.*/ frame.pack(); frame.setVisible(true); }而不是添加它们。这是我目前拥有的代码的相关部分（注释易读性）：

frame.add([some component])

我已经尝试在frame.pack()之前致电Group，但它从未产生任何明显的差异。我查看了GroupLayout的官方文档，我认为无法访问或更改GroupLayout中的水平/垂直Group，甚至是Layout引用的字段Code import matplotlib.pyplot as plt fig, ax = plt.subplots() ax.plot([1, 2, 3, 4, 5], [50, 40, 60, 70, 50]) plt.show()就此而言。我完全不知道该怎么做。如果可能的话，我想避免学习一种新型的select max(avg_value) from ( SELECT AVG(amount) avg_value FROM orders GROUP BY cust ) tmp，但是我开始害怕我必须（或者更糟糕的是，那就是我所做的事情）。我试图做的事情是不可能的。）

Answer 1

如图here所示，您可以使用此方法：

首先，创建必需的ParallelGroup和SequentialGroup。
稍后，添加代表新行的所需组和组件。

在下面的示例中，add()会在布局中附加新的标签和文本字段。建议here的AdjustmentListener滚动到最后添加的行。

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.AdjustmentEvent;
import javax.swing.AbstractAction;
import javax.swing.GroupLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextField;

/**
 * @see https://stackoverflow.com/a/41926375/230513
 * @see https://stackoverflow.com/a/14858272/230513
 * @see https://stackoverflow.com/a/8504753/230513
 * @see https://stackoverflow.com/a/14011536/230513
 */
public class DynamicGroupLayout {

    private static final int NUM = 6;
    private GroupLayout layout;
    private GroupLayout.ParallelGroup parallel;
    private GroupLayout.SequentialGroup sequential;
    private int i;

    private JPanel create() {
        JPanel panel = new JPanel();
        layout = new GroupLayout(panel);
        panel.setLayout(layout);
        layout.setAutoCreateGaps(true);
        layout.setAutoCreateContainerGaps(true);
        parallel = layout.createParallelGroup();
        layout.setHorizontalGroup(layout.createSequentialGroup().addGroup(parallel));
        sequential = layout.createSequentialGroup();
        layout.setVerticalGroup(sequential);
        for (int i = 0; i < NUM; i++) {
            add();
        }
        return panel;
    }

    private void add() {
        JLabel label = new JLabel(String.valueOf(i + 1), JLabel.RIGHT);
        JTextField field = new JTextField(String.valueOf("String " + (i + 1)));
        label.setLabelFor(field);
        parallel.addGroup(layout.createSequentialGroup().
            addComponent(label).addComponent(field));
        sequential.addGroup(layout.createParallelGroup(GroupLayout.Alignment.BASELINE).
            addComponent(label).addComponent(field));
        i++;
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                JFrame f = new JFrame("DynamicGroupLayout");
                f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                final DynamicGroupLayout dgl = new DynamicGroupLayout();
                final JPanel panel = dgl.create();
                JScrollPane jsp = new JScrollPane(panel) {
                    @Override
                    public Dimension getPreferredSize() {
                        return new Dimension(320, 240);
                    }
                };
                jsp.getVerticalScrollBar().addAdjustmentListener((AdjustmentEvent e) -> {
                    e.getAdjustable().setValue(e.getAdjustable().getMaximum());
                });
                f.add(jsp);
                JPanel controls = new JPanel();
                controls.add(new JButton(new AbstractAction("Add") {
                    @Override
                    public void actionPerformed(ActionEvent e) {
                        dgl.add();
                        panel.validate();
                    }
                }));
                f.add(controls, BorderLayout.SOUTH);
                f.pack();
                f.setLocationRelativeTo(null);
                f.setVisible(true);
            }
        });
    }
}

可以将组件动态添加到GroupLayout中的组吗？

1 个答案: