java - JDK7半透明+jframe+jcombobox

Question

当我在使用半透明的 jFrame 中有一个 jComboBox 时，似乎存在问题。当我单击下拉列表时，出现白色背景以覆盖其他组件，但未显示下拉列表中的项目。每个项目只有在我的鼠标悬停在它上面时才会出现。边界似乎也不在附近。

有什么解决方法吗？

谢谢！

Answer 1

我也面临同样的问题。

快速解决：

import java.awt.*;
import javax.swing.*;
import javax.swing.event.*;
class WindowOpaqueTest2{
  public JComponent makeUI() {
    JPanel p = new JPanel();
    p.setBackground(new Color(.5f,.5f,.5f,.5f));
    p.add(new JComboBox<String>(new String[] {"aaa", "bb", "c"}));
    JComboBox c = new JComboBox<String>(new String[] {"aaa", "bb", "c"});
    c.addPopupMenuListener(new PopupMenuListener() {
      @Override public void popupMenuWillBecomeVisible(final PopupMenuEvent e) {
        EventQueue.invokeLater(new Runnable() {
          @Override public void run() {
            JComboBox c = (JComboBox)e.getSource();
            Object o = c.getAccessibleContext().getAccessibleChild(0);
            if(o instanceof JComponent) { //BasicComboPopup
              ((JComponent)o).repaint();
            }
          }
        });
      }
      @Override public void popupMenuWillBecomeInvisible(PopupMenuEvent e) {}
      @Override public void popupMenuCanceled(PopupMenuEvent e) {}
    });
    p.add(c);
    return p;
  }
  public static void main(String[] args) {
    EventQueue.invokeLater(new Runnable() {
      @Override public void run() { createAndShowGUI(); }
    });
  }
  public static void createAndShowGUI() {
    JFrame.setDefaultLookAndFeelDecorated(true);
    JFrame f = new JFrame();
    //com.sun.awt.AWTUtilities.setWindowOpaque(f, false);
    f.setBackground(new Color(0,true)); //1.7.0
    f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    f.getContentPane().add(new WindowOpaqueTest2().makeUI());
    f.setSize(320, 240);
    f.setLocationRelativeTo(null);
    f.setVisible(true);
  }
}