引用来自NSManagedObjectContext文档的-undo方法：
Sends an undo message to the receiver’s undo manager,asking it to reverse the latest uncommitted changes applied to objects in the object graph.
要扭转最新的未提交更改,听起来很简单吧？
但是,实际情况并非如此！即使我使用托管对象上的更改保存上下文,以下-undo调用仍将成功撤消更改.这不是针对文档中陈述的内容吗？
也许我做错了什么？如果需要,我可以发布我的小测试代码.我真的很困惑.
解决方法
核心数据编程指南更详细：
Change and Undo Management
A context keeps strong references to managed objects that have pending
changes (insertions,deletions,or updates) until the context is sent
a save:,reset,rollback,or dealloc message,or the appropriate
number of undos to undo the change.The undo manager associated with a context keeps strong references to
any changed managed objects. By default,in OS X the context’s undo
manager keeps an unlimited undo/redo stack. To limit your
application’s memory footprint,you should make sure that you scrub
(usingremoveAllActions) the context’s undo stack as and when
appropriate. Unless you keep a strong reference to a context’s undo
manager,it is deallocated with its context.
文档中的措辞/词汇不清晰或不一致.我相信,在适合您的应用程序时,您应该在上下文的undoManager属性上调用removeAllActions,以避免无限的内存增长.
