java - 在 JPanel 中使用 GlassPane

Question

我想使用 glassPane 函数在加载数据期间停用面板中的组件。我知道玻璃板仅适用于框架。在我的应用程序中，我无法访问该框架。我只想停用框架中的单个面板。

我尝试通过重写面板的paint或paintComponent方法在面板上绘制矩形。问题是底层组件仍然可用。

谁能给我建议如何解决这个问题？

问候

数据库

Answer 1

一种可能性 - 使用 JLayeredPane 包围您的 JPanel，然后激活位于其上方的 JPanel 层，让它窃取焦点和 MouseListener。例如:

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.event.MouseAdapter;

import javax.swing.*;

public class MyGlassPaneWrapper extends JLayeredPane {
   private JPanel glassPanel = new JPanel();

   public MyGlassPaneWrapper(JComponent myPanel) {
      glassPanel.setOpaque(false);
      glassPanel.setVisible(false);
      glassPanel.addMouseListener(new MouseAdapter() {});
      glassPanel.setFocusable(true);

      myPanel.setSize(myPanel.getPreferredSize());
      add(myPanel, JLayeredPane.DEFAULT_LAYER);
      add(glassPanel, JLayeredPane.PALETTE_LAYER);

      glassPanel.setPreferredSize(myPanel.getPreferredSize());
      glassPanel.setSize(myPanel.getPreferredSize());
      setPreferredSize(myPanel.getPreferredSize());
   }

   public void activateGlassPane(boolean activate) {
      glassPanel.setVisible(activate);
      if (activate) {
         glassPanel.requestFocusInWindow();
         glassPanel.setFocusTraversalKeysEnabled(false);
      } 
   }

   private static void createAndShowGui() {
      final MyPanel myPanel = new MyPanel();
      final MyGlassPaneWrapper myGlassPaneWrapper = new MyGlassPaneWrapper(myPanel);
      final String activateGlassPane = "Activate GlassPane";
      final String deactivateGlassPane = "Deactivate GlassPane";

      JToggleButton toggleButton = new JToggleButton(activateGlassPane);
      toggleButton.addItemListener(new ItemListener() {

         @Override
         public void itemStateChanged(ItemEvent e) {
            AbstractButton source = (AbstractButton) e.getSource();
            if (e.getStateChange() == ItemEvent.SELECTED) {
               source.setText(deactivateGlassPane);
               myGlassPaneWrapper.activateGlassPane(true);
            } else {
               source.setText(activateGlassPane);
               myGlassPaneWrapper.activateGlassPane(false);
            }
         }
      });
      JPanel buttonPanel = new JPanel();
      buttonPanel.add(toggleButton);

      JFrame frame = new JFrame("MyGlassPane");
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.getContentPane().add(myGlassPaneWrapper);
      frame.getContentPane().add(buttonPanel, BorderLayout.PAGE_END);
      frame.pack();
      frame.setLocationRelativeTo(null);
      frame.setVisible(true);
   }

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

class MyPanel extends JPanel {

   public MyPanel() {
      add(new JTextField(5));
      add(new JComboBox<String>(new String[]{"Monday", "Tuesday", "Wednesday"}));
      add(new JButton(new AbstractAction("Push Me") {

         @Override
         public void actionPerformed(ActionEvent e) {
            JOptionPane.showMessageDialog(MyPanel.this, "Button Pushed");
         }
      }));
   }
}