iOS8 CoreData“使用未实现的初始化器” [英] iOS8 CoreData "use of unimplemented initializer"

问题描述

尝试运行我的应用程序时出现以下错误

致命错误：对'rcresttest.CatalogItem类使用未实现的初始化器'init（entity：insertIntoManagedObjectContext :)' '

我可以绕过这个错误，通过改变数据模型中的Entity的类别，但是我会得到一个swift_dynamicCastClassUnconditional：当试图downcast。 >

这是beta6中的错误还是我做错了？

CatalogItem.swift

  import CoreData 
 
 @objc（CatalogItem）
 
 class CatalogItem：NSManagedObject {
 @ NSManaged var id：String 
 @NSManaged var slug：String 
 @NSManaged var catalogItemId：String 
 
 init（entity：NSEntityDescription !, context：NSManagedObjectContext !, catalogResultsDict：NSDictionary）{ 
 super.init（entity：entity，insertIntoManagedObjectContext：context）
 id = catalogResultsDict [Id] as String 
 slug = catalogResultsDict [Slug] as String 
 catalogItemId = catalogResultsDict [CatalogItemId] as String 
} 
} 
  

 <？xml version =1.0encoding =UTF-8standalone =yes？> 
< model userDefinedModelVersionIdentifier =type =com.apple.IDECoreDataModeler.DataModeldocumentVersion =1.0lastSavedToolsVersion =6220.8systemVersion =13E28minimumToolsVersion =Xcode 4.3macOSVersion =Automatic 自动> 
< entity name =CatalogItem \"resentClassName =CatalogItemsyncable =YES> 
< attribute name =catalogItemIdoptional =YESattributeType =Stringsyncable =YES/> 
< attribute name =idoptional =YESattributeType =Stringsyncable =YES/> 
< attribute name =slugoptional =YESattributeType =Stringsyncable =YES/> 
< / entity> 
< elements> 
< element name =CatalogItempositionX = -  45positionY =0width =128height =90/> 
< / elements> 
< / model> 
  

编辑：

2014-08-20 10：49：15.335 rcresttest [63516：4194127] CoreData ：warning：无法加载实体'CatalogItem'命名为'rcresttest.CatalogItem'的类。类未找到，使用默认NSManagedObject。

解决方案

这是指定的初始化程序的问题。只需在 init 前添加方便并调用 init（entity：insertIntoManagedObjectContext：）

I get the following error trying to run my application

fatal error: use of unimplemented initializer 'init(entity:insertIntoManagedObjectContext:)' for class 'rcresttest.CatalogItem'

I can bypass this error by changing the Entity's class in the data model to something else, but then I will get a swift_dynamicCastClassUnconditional: when trying to downcast.

Is this a bug in beta6 or am I doing something wrong?

CatalogItem.swift

import CoreData

@objc(CatalogItem)

class CatalogItem : NSManagedObject {
    @NSManaged var id : String
    @NSManaged var slug : String
    @NSManaged var catalogItemId : String

    init(entity: NSEntityDescription!, context: NSManagedObjectContext!, catalogResultsDict : NSDictionary) {
       super.init(entity: entity, insertIntoManagedObjectContext: context)
       id = catalogResultsDict["Id"] as String
       slug = catalogResultsDict["Slug"] as String
       catalogItemId = catalogResultsDict["CatalogItemId"] as String
    }
}

and the data model

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<model userDefinedModelVersionIdentifier="" type="com.apple.IDECoreDataModeler.DataModel" documentVersion="1.0" lastSavedToolsVersion="6220.8" systemVersion="13E28" minimumToolsVersion="Xcode 4.3" macOSVersion="Automatic" iOSVersion="Automatic">
    <entity name="CatalogItem" representedClassName="CatalogItem" syncable="YES">
        <attribute name="catalogItemId" optional="YES" attributeType="String" syncable="YES"/>
        <attribute name="id" optional="YES" attributeType="String" syncable="YES"/>
        <attribute name="slug" optional="YES" attributeType="String" syncable="YES"/>
    </entity>
    <elements>
        <element name="CatalogItem" positionX="-45" positionY="0" width="128" height="90"/>
    </elements>
</model>

Edit:

After changing the name of the datamodel class to have the module prefix The error message appears after trying to cast.

2014-08-20 10:49:15.335 rcresttest[63516:4194127] CoreData: warning: Unable to load class named 'rcresttest.CatalogItem' for entity 'CatalogItem'. Class not found, using default NSManagedObject instead.

解决方案

This is a problem with the designated initializer. Just add convenience in front of your init and call init(entity:insertIntoManagedObjectContext:) on self instead super.

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