最终使用滚动条的JPanel列表 [英] List of JPanels that eventually uses a scrollbar

问题描述

我正在尝试为我的Java应用程序构建GUI。
我动态添加JPanels，这是我GUI中的行。在面板列表下面有一个添加新面板的按钮。随着List的增长，它到达父Container的末尾。然后我想使用滚动条，以便用户能够到达列表中的每个面板。

im trying to build a GUI for my Java application. I dynamically add JPanels, which are a "row" in my GUI. Under the List of the Panels there is a button to add a new Panel. As the List grows, it reaches the end of the parent Container. Then I want to use scrollbars, so that the user is able to reach every panel in the List.

到目前为止，我尝试使用JScrollPanes和Layouts，但我不知道如何让它运转起来。

So far I experimented with JScrollPanes and Layouts but I have no Idea how to get it working.

你能给我一些建议吗？

this.setLayout(new BorderLayout());
JPanel listContainer = new JPanel();
listContainer.setLayout(BoxLayout(listContainer, BoxLayout.Y_AXIS);

this.add(new JScrollPane(listContainer), BorderLayout.CENTER);
this.add(new JButton(), BorderLayout.PAGE_END);

//then i add panels to the listContainer. this wont work, when the space is complettly used there is no scrollbar.

推荐答案

很难从你的代码片段确切地知道你可能遇到问题的地方。

It's difficult to assertain from your code snippet exactly where you might be having problems.

public class DynamicPanelList {

    public static void main(String[] args) {
        new DynamicPanelList();
    }

    public DynamicPanelList() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (Exception ex) {
                }

                JFrame frame = new JFrame("Test");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        private JPanel mainList;

        public TestPane() {
            setLayout(new BorderLayout());

            mainList = new JPanel(new GridBagLayout());
            GridBagConstraints gbc = new GridBagConstraints();
            gbc.gridwidth = GridBagConstraints.REMAINDER;
            gbc.weightx = 1;
            gbc.weighty = 1;
            mainList.add(new JPanel(), gbc);

            add(new JScrollPane(mainList));

            JButton add = new JButton("Add");
            add.addActionListener(new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    JPanel panel = new JPanel();
                    panel.add(new JLabel("Hello"));
                    panel.setBorder(new MatteBorder(0, 0, 1, 0, Color.GRAY));
                    GridBagConstraints gbc = new GridBagConstraints();
                    gbc.gridwidth = GridBagConstraints.REMAINDER;
                    gbc.weightx = 1;
                    gbc.fill = GridBagConstraints.HORIZONTAL;
                    mainList.add(panel, gbc, 0);

                    validate();
                    repaint();
                }
            });

            add(add, BorderLayout.SOUTH);

        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(200, 200);
        }
    }
}

你真的需要提供一个 SSCCE ，这将使我们能够诊断您遇到的问题。

You really need to provide a SSCCE which would allow us to diagnose the problems you are having.

就个人而言，这将取决于您的要求，更好的布局管理器可能是来自SwingLabs SwingX库的 VerticalLayout 。

Personally, and this will depend on you requirements, a better layout manager might be VerticalLayout from SwingLabs SwingX libraries.

这篇关于最终使用滚动条的JPanel列表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IT屋！