除了您不发布完整源代码或 SSCCE 我无法完全测试.

Well besides the fact that you dont post your full source or an SSCCE I cannot fully test.

查看代码，您正在使用removeAll()方法在单个JFrame/容器上的多个JPanel之间切换.

Looking at your code you are using the removeAll() method to switch between multiple JPanels on a single JFrame/container.

我看到的错误是逻辑上的，因为您试图在另一个JPanel而不是实际的JFrame中的JPanel之间切换.

The mistake I see you are making though is in the logic, as you attempt to switch between JPanels within another JPanel rather than within your actual JFrame.

请参阅我创建的这个小示例(允许用户在一个实现JFrame/ container 上，在2个JPanel之间切换". wikipedia.org/wiki/Singleton_pattern"rel =" nofollow noreferrer>单一设计模式，可以很容易地进行更改，以便将MainGUI类的实例传递给每个JPanel和MainGUI生成的对象，从而使 s将可以访问单个MainGUI s swapPanel(JPanel p)方法):

See this small example I created (allows a user to alternate between 2 JPanels on a single JFrame/container which implements a Singleton design pattern, can easily be changed for passing instance of MainGUI class to each JPanel the MainGUI spawns so that the JPanels will have access to the single MainGUIs swapPanel(JPanel p) method):

import java.awt.event.ActionEvent;
import javax.swing.AbstractAction;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;


public class Test {

    public static void main(String[] args) {
        MainGUI mainGUI = MainGUI.getInstance();
    }
}
class MainGUI {

    private JFrame frame;

    private static class SingletonHolder {

        public static final MainGUI INSTANCE = new MainGUI();
    }

    public static MainGUI getInstance() {
        return SingletonHolder.INSTANCE;
    }

    private MainGUI() {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                frame = createJFrame();
                frame.setVisible(true);
            }
        });
    }

    private JFrame createJFrame() {
        frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setTitle("Test");

        frame.add(new Panel1());//initial Jpanel to display

        frame.pack();
        return frame;
    }

    public void swapPanel(JPanel p) {
        frame.getContentPane().removeAll();
        frame.add(p);
        frame.pack();
        frame.revalidate();
        frame.repaint();
    }
}

class Panel1 extends JPanel {

    public Panel1() {
        JLabel labelPanel1 = new JLabel("Panel 1");
        JButton switchPanelButton = new JButton("Goto Panel 2");
        switchPanelButton.addActionListener(new AbstractAction() {
            @Override
            public void actionPerformed(ActionEvent e) {
                MainGUI.getInstance().swapPanel(new Panel2());
            }
        });
        add(labelPanel1);
        add(switchPanelButton);
    }
}

class Panel2 extends JPanel {

    public Panel2() {
        JLabel labelPanel1 = new JLabel("Panel 2");
        JButton switchPanelButton = new JButton("Goto Panel 1");
        switchPanelButton.addActionListener(new AbstractAction() {
            @Override
            public void actionPerformed(ActionEvent e) {
                MainGUI.getInstance().swapPanel(new Panel1());
            }
        });
        add(labelPanel1);
        add(switchPanelButton);
    }
}

上述的更高级替代方法是 CardLayout CardLayout类管理共享相同显示空间的两个或更多组件(通常是JPanel实例).:

An higher-level alternative to the above is a CardLayout The CardLayout class manages two or more components (usually JPanel instances) that share the same display space.:

import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

public class Test {

    private final static String PANEL1 = "panel 1";
    private final static String PANEL2 = "panel 2";

    public Test() {
        initComponents();
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                new Test();
            }
        });
    }

    private void initComponents() {
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JPanel panel1 = new JPanel();
        panel1.add(new JLabel("Panel 1"));

        JPanel panel2 = new JPanel();
        panel2.add(new JLabel("Panel 2"));

        //Create the panel that contains the "cards".
        final JPanel cards = new JPanel(new CardLayout());
        cards.add(panel1, PANEL1);
        cards.add(panel2, PANEL2);

        //create button to allow chnage to next card
        JButton buttonNext = new JButton(">");
        buttonNext.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent ae) {
                CardLayout cl = (CardLayout) (cards.getLayout());//get cards
                cl.next(cards);
            }
        });

        //create button to allow chnage to previous card
        JButton buttonPrev = new JButton("<");
        buttonPrev.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent ae) {
                CardLayout cl = (CardLayout) (cards.getLayout());//get cards
                cl.previous(cards);
            }
        });

        //create panel to hold buttons which will allow switching between cards
        JPanel buttonPanel = new JPanel();
        buttonPanel.add(buttonPrev);
        buttonPanel.add(buttonNext);


        frame.add(cards);
        frame.add(buttonPanel, BorderLayout.SOUTH);

        frame.pack();
        frame.setVisible(true);
    }
}