我在这里有点猜测,但是......Graphics2D ga = (Graphics2D)g2.create();ga.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, rail0FlashList.get(fl)));// Use ga to render what ever needs to be painted with the alpha compositega.dispose();基本上它的作用是,它创建Graphics状态的快照,允许您修改它,而不会影响原始上下文的状态。它在处理转换时也非常有用