我对NSManagedObjectContext的类型有些疑惑，我们看看apple关于NSConfinementConcurrencyType的文档:Confinement(NSConfinementConcurrencyType)Forbackwardscompatibility,thisisthedefault.Youpromisethatcontextwillnotbeusedbyanythreadotherthantheoneonwhichyoucreatedit.Ingeneral,tomakethebehaviorexplicityou’reencouragedtouseo