带卷轴的2 JPanels

Question

所以我把这个面板放置在我的框架的顶部(北)边，叫做menupanel。在这个面板中，我还有另外两个面板- topPanel和botPanel (红色和黑色)。在这两个面板中都有几个按钮(在本例中为标签)。我想增加滚动(水平)在两个面板(机器人和顶部)。

// creating the frame
    JFrame frame;
    frame = new JFrame("Test");
    frame.setVisible(true);
    frame.setLayout(new BorderLayout());
    frame.setSize(600, 400);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    // creating labels

            JLabel label1 = new JLabel("TEXT TEXT TEXT TEXT TEXT TEXT TEXT TEXT TEXT TEXT TEXT TEXT TEXT");
            JLabel label2 = new JLabel("TEXT2 TEXT2 TEXT2 TEXT2 TEXT2 TEXT2 TEXT2 TEXT2 TEXT2 TEXT2 TEXT2 TEXT2 TEXT2");
            JLabel label3 = new JLabel("TEXT3 TEXT3 TEXT3 TEXT3 TEXT3 TEXT3 TEXT3 TEXT3 TEXT3 TEXT3 TEXT3 TEXT3 TEXT3");

            JLabel label4 = new JLabel("TEXT TEXT TEXT TEXT TEXT TEXT TEXT TEXT TEXT TEXT TEXT TEXT TEXT");
            JLabel label5 = new JLabel("TEXT2 TEXT2 TEXT2 TEXT2 TEXT2 TEXT2 TEXT2 TEXT2 TEXT2 TEXT2 TEXT2 TEXT2 TEXT2");
            JLabel label6 = new JLabel("TEXT3 TEXT3 TEXT3 TEXT3 TEXT3 TEXT3 TEXT3 TEXT3 TEXT3 TEXT3 TEXT3 TEXT3 TEXT3");

    // creating the main and menu panel

    JPanel menupanel,topPanel,botPanel,mainpanel;
    mainpanel = new JPanel();
    menupanel = new JPanel(new BorderLayout());
    topPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
    botPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));

    topPanel.setPreferredSize(new Dimension(300, 100));
    botPanel.setPreferredSize(new Dimension(300, 100));

    topPanel.add(label1);
    topPanel.add(label2);
    topPanel.add(label3);

    botPanel.add(label4);
    botPanel.add(label5);
    botPanel.add(label6);

    topPanel.setBackground(Color.RED);
    botPanel.setBackground(Color.BLACK);
    mainpanel.setBackground(Color.BLUE);


    JScrollPane scrollT,scrollB;
    scrollT = new JScrollPane(topPanel);
    scrollT.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
    scrollB = new JScrollPane(botPanel);
    scrollB.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
    menupanel.add(scrollT);
    menupanel.add(scrollB);

    menupanel.add( topPanel, BorderLayout.NORTH );
    menupanel.add( botPanel, BorderLayout.SOUTH );


    frame.add(mainpanel, BorderLayout.CENTER);
    frame.add(menupanel, BorderLayout.NORTH);
    frame.pack();

你可以在这里看到一幅图像

Answer 1

您要向多个容器中添加组件：

scrollT = new JScrollPane(topPanel);  // topPanel added to scroll pane
scrollT.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
scrollB = new JScrollPane(botPanel);  // botPanel added to scroll pane
scrollB.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
menupanel.add(scrollT); // scrollpanes added to menupanel -- without Borderlayout constants?
menupanel.add(scrollB);

menupanel.add( topPanel, BorderLayout.NORTH );  // topPanel added to menupanel
menupanel.add( botPanel, BorderLayout.SOUTH );

Swing GUI不允许这样做。

相反，将topPanel和botPanel添加到JScrollPanes中，将JScrollPanes添加到GUI的其余部分，但不要将topPanel和botPanel重新添加到任何东西中。

另一个问题--你限制了topPanel和僵尸面板的大小，这会使它们不滚动--避免这样做。如果需要限制某物的大小，请执行滚动窗格的视图或滚动窗格本身。

例如，

import java.awt.Dimension;
import java.awt.GridLayout;

import javax.swing.*;

public class ScrollPaneFun2 extends JPanel {

    private static final int PREF_W = 500;

    public ScrollPaneFun2() {
        JPanel topPanel = new JPanel(new GridLayout(0, 1));
        JPanel botPanel = new JPanel(new GridLayout(0, 1));

        for (int i = 0; i < 3; i++) {
            JPanel innerTopPanel = new JPanel(new GridLayout(1, 0, 3, 0));
            JPanel innerBotPanel = new JPanel(new GridLayout(1, 0, 3, 0));
            for (int j = 0; j < 50; j++) {
                innerTopPanel.add(new JLabel("Text " + (i + 1)));
                innerBotPanel.add(new JLabel("Text " + (i + 1)));
            }
            topPanel.add(innerTopPanel);
            botPanel.add(innerBotPanel);
        }

        JScrollPane topScrollPane = new JScrollPane(topPanel);
        JScrollPane botScrollPane = new JScrollPane(botPanel);
        topScrollPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
        botScrollPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);

        setLayout(new GridLayout(0, 1));
        add(topScrollPane);
        add(botScrollPane);
    }

    @Override
    public Dimension getPreferredSize() {
        if (isPreferredSizeSet()) {
            return super.getPreferredSize();
        }
        int height = super.getPreferredSize().height;
        return new Dimension(PREF_W, height);
    }

    private static void createAndShowGui() {
        JFrame frame = new JFrame("ScrollPaneFun2");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().add(new ScrollPaneFun2());
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> createAndShowGui());
    }
}