从iOS中的xcdatamodel访问FetchRequest [英] Access FetchRequest from xcdatamodel in iOS

问题描述

我正在使用NSPersistentContainer访问iOS10应用程序和Xcode 8中的核心数据.与实体类似，我在Coredata xcdatamodel中添加了"UserFetchRequest".下面是屏幕截图.

I'm using NSPersistentContainer to access my core data in iOS10 app and Xcode 8. Similar to Entity, I added a "UserFetchRequest" in my Coredata xcdatamodel. Below is the screen shot.

如何访问代码中的"UserFetchRequest"?

How can I access the "UserFetchRequest" in the code?

推荐答案

在右侧的数据模型检查器中为您的提取请求指定了名称:

Having given your fetch request a name in the Data Model Inspector on the right hand side:

(在我的情况下为"randomFetch"，其中您的名称为"UserFetchRequest")，从persistentContainer获取模型:

(in my case named "randomFetch" where yours is "UserFetchRequest"), get the model from the persistentContainer:

let model = persistentContainer.managedObjectModel

，然后使用 fetchRequestTemplate(forName:)方法访问提取请求:

and then access the fetch request using the fetchRequestTemplate(forName:) method:

let fetchRequest = model.fetchRequestTemplate(forName: "randomFetch") as! NSFetchRequest<Event>

然后您可以照常执行此提取请求.

You can then execute this fetch request as normal.

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