NSManagedObjectContextObjectsDidChangeNotification不总是立即调用 [英] NSManagedObjectContextObjectsDidChangeNotification not always called instantly

问题描述

我有一个Mac应用程序使用NSPersistentDocument。我想在对象被删除时收到通知，以使用Core Data保存此信息。所以我正在听NSManagedObjectContextObjectsDidChangeNotification。通常，当对象被删除时，它被立即调用，但有时它仅在持久文档被保存之后被调用，所有被删除的对象不被通知。因为我想让用户直接导出所有现有对象（而不是已删除的），我必须做什么才能立即通知保存删除信息，或者我必须以另一种方式使用它？

$ NSManagedObjectContextObjectsDidChangeNotification不再频繁或快速地在10.7上与10.6中发布的那样发布。

您可以通过调用 - [NSManagedObjectContext processPendingChanges] 来强制Core Data发出通知（假设有更改）。

I have an Mac Application using a NSPersistentDocument. I want to get notified when Objects are deleted to save this information using Core Data. So I'm listening for NSManagedObjectContextObjectsDidChangeNotification. Often it is called instantly when objects are deleted, but sometimes it is only called after the persistent document is saved with all deleted objects not being notified before. Because I want to let the user directly export all existing objects (and not the deleted anymore) what to I have to do to become notified instantly to save the delete information or do I have to use it in another way?

解决方案

NSManagedObjectContextObjectsDidChangeNotification is no longer issued as frequently or quickly on 10.7 as on 10.6. You can force Core Data to issue the notification (assuming there are changes) by calling -[NSManagedObjectContext processPendingChanges].

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