Find centralized, trusted content and collaborate around the technologies you use most.
Teams
Q&A for work
Connect and share knowledge within a single location that is structured and easy to search.
(单击屏幕截图以查看更大的版本。)
我在第 251 行上的 getActiveState() 方法和 getColumn(x, y) 方法之前已经过测试并且可以正常工作,所以我不明白为什么我现在会收到错误消息。谁能解释一下?
我认为 NullPointerException 发生在以下代码行中
251 号线
this.region.getColumn(x, y) // is null for some kind of columns ...