Java 更改JComboBox中滚动条的大小

有人知道如何手动更改jComboBox中的滚动条大小吗？我试过很多东西，但都不管用

好吧，我想出来了。您可以实现PopUpMenuListener并使用：

   public void popupMenuWillBecomeVisible(PopupMenuEvent e)
   {
      JComboBox comboBox = (JComboBox) e.getSource();
      Object popup = comboBox.getUI().getAccessibleChild(comboBox, 0);
      Component c = ((Container) popup).getComponent(0);
      if (c instanceof JScrollPane)
      {
         JScrollPane scrollpane = (JScrollPane) c;
         JScrollBar scrollBar = scrollpane.getVerticalScrollBar();
         Dimension scrollBarDim = new Dimension(SCROLLBAR_WIDTH, scrollBar
               .getPreferredSize().height);
         scrollBar.setPreferredSize(scrollBarDim);
      }
   }