核心数据NSManagedObject没有一个有效的NSEntityDescription

Question

我想用我的Xcode项目设置核心数据，并运行一个我似乎无法摆脱的错误。我在StudyHub.xcdatamodeld内部有一个名为UserDetails的实体。我在AppDelegate的代码：

// MARK: - Core Data stack 

lazy var persistentContainer: NSPersistentContainer = { 
    /* 
    The persistent container for the application. This implementation 
    creates and returns a container, having loaded the store for the 
    application to it. This property is optional since there are legitimate 
    error conditions that could cause the creation of the store to fail. 
    */ 
    let container = NSPersistentContainer(name: "DELETE") 
    container.loadPersistentStores(completionHandler: { (storeDescription, error) in 
     if let error = error as NSError? { 
      // Replace this implementation with code to handle the error appropriately. 
      // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. 

      /* 
      Typical reasons for an error here include: 
      * The parent directory does not exist, cannot be created, or disallows writing. 
      * The persistent store is not accessible, due to permissions or data protection when the device is locked. 
      * The device is out of space. 
      * The store could not be migrated to the current model version. 
      Check the error message to determine what the actual problem was. 
      */ 
      fatalError("Unresolved error \(error), \(error.userInfo)") 
     } 
    }) 
    return container 
}() 

// MARK: - Core Data Saving support 

func saveContext() { 
    let context = persistentContainer.viewContext 
    if context.hasChanges { 
     do { 
      try context.save() 
     } catch { 
      // Replace this implementation with code to handle the error appropriately. 
      // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. 
      let nserror = error as NSError 
      fatalError("Unresolved error \(nserror), \(nserror.userInfo)") 
     } 
    } 
} 

// MARK: Send Data to CoreData 

func saveUserDetails(data: [String: String]) { 
    let appDelegate = UIApplication.shared.delegate as! AppDelegate 
    let context = appDelegate.persistentContainer.viewContext 
    let user = UserDetails(context: context) 
    if let authenticatedWith = data["authenticatedWith"] { 
     user.authenticatedWith = authenticatedWith 
    } 
    if let email = data["email"] { 
     user.email = email 
    } 
    if let fullName = data["fullName"] { 
     user.fullName = fullName 
    } 
    if let username = data["username"] { 
     user.username = username 
    } 
    if let schoolName = data["schoolName"] { 
     user.schoolName = schoolName 
    } 
    if let schoolUID = data["schoolUID"] { 
     user.schoolUID = schoolUID 
    } 
    if let facebookLink = data["facebookLink"] { 
     user.facebookLink = facebookLink 
    } 
    if let twitterLink = data["twitterLink"] { 
     user.twitterLink = twitterLink 
    } 
    if let instagramLink = data["instagramLink"] { 
     user.instagramLink = instagramLink 
    } 
    if let vscoLink = data["vscoLink"] { 
     user.vscoLink = vscoLink 
    } 
    appDelegate.saveContext() 
} 

我检索存储在一个视图控制器内的数据代码：

let user = UserDetails() 

if (user.username != "") { 
    self.navigationItem.title = user.username 
} else { 
    self.navigationItem.title = "Account." 
} 
self.usersNameLabel.text = user.fullName 
if (user.schoolName != "") { 
    self.usersSchoolNameLabel.setTitle(user.schoolName, for: .normal) 
    self.usersSchoolNameLabel.isHidden = false 
} else { 
    self.addSchoolButton.isHidden = false 
} 
self.checkSocialLink(link: user.facebookLink!, button: self.facebookLinkButton) // TODO: Force unwrap might not work 
self.checkSocialLink(link: user.twitterLink!, button: self.twitterLinkButton) 
self.checkSocialLink(link: user.instagramLink!, button: self.instagramLinkButton) 
self.checkSocialLink(link: user.vscoLink!, button: self.vscoLinkButton) 

我得到的错误：

2017-01-13 21:22:58.675995 StudyHub[3328:27695] [error] error: Failed to load model named DELETE 
CoreData: error: Failed to load model named DELETE 
2017-01-13 21:22:58.699 StudyHub[3328:27695] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'An NSManagedObject of class 'UserDetails' must have a valid NSEntityDescription.' 
*** First throw call stack: 
(
0 CoreFoundation      0x0000000114fa2d4b __exceptionPreprocess + 171 
1 libobjc.A.dylib      0x0000000114a0b21e objc_exception_throw + 48 
2 CoreData       0x000000010ffe0fb0 -[NSManagedObject initWithEntity:insertIntoManagedObjectContext:] + 528 
3 StudyHub       0x000000010edee13c _TFC8StudyHub11UserDetailscfT6entityCSo19NSEntityDescription10insertIntoGSqCSo22NSManagedObjectContext__S0_ + 76 
4 StudyHub       0x000000010edee212 _TToFC8StudyHub11UserDetailscfT6entityCSo19NSEntityDescription10insertIntoGSqCSo22NSManagedObjectContext__S0_ + 66 
5 CoreData       0x0000000110082d79 -[NSManagedObject initWithContext:] + 793 
6 StudyHub       0x000000010ed05dd4 _TTOFCSo15NSManagedObjectcfT7contextCSo22NSManagedObjectContext_S_ + 36 
7 StudyHub       0x000000010ed0211c _TFCSo15NSManagedObjectCfT7contextCSo22NSManagedObjectContext_S_ + 76 
8 StudyHub       0x000000010ed009e5 _TFFC8StudyHub11AppDelegate11applicationFTCSo13UIApplication29didFinishLaunchingWithOptionsGSqGVs10DictionaryVSC29UIApplicationLaunchOptionsKeyP____SbL_15saveUserDetailsFT4dataGS2_SSSS__T_ + 421 
9 StudyHub       0x000000010ed02837 _TFFC8StudyHub11AppDelegate11applicationFTCSo13UIApplication29didFinishLaunchingWithOptionsGSqGVs10DictionaryVSC29UIApplicationLaunchOptionsKeyP____SbU1_FCSo15FIRDataSnapshotT_ + 1607 
10 StudyHub       0x000000010ed0290c _TTRXFo_oCSo15FIRDataSnapshot__XFdCb_dS___ + 60 
11 StudyHub       0x000000010eedb4af __43-[FValueEventRegistration fireEvent:queue:]_block_invoke.57 + 78 
12 libdispatch.dylib     0x0000000115df3978 _dispatch_call_block_and_release + 12 
13 libdispatch.dylib     0x0000000115e1d0cd _dispatch_client_callout + 8 
14 libdispatch.dylib     0x0000000115dfd8a4 _dispatch_main_queue_callback_4CF + 406 
15 CoreFoundation      0x0000000114f66e49 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 9 
16 CoreFoundation      0x0000000114f2c37d __CFRunLoopRun + 2205 
17 CoreFoundation      0x0000000114f2b884 CFRunLoopRunSpecific + 420 
18 GraphicsServices     0x0000000117ba4a6f GSEventRunModal + 161 
19 UIKit        0x00000001131bfc68 UIApplicationMain + 159 
20 StudyHub       0x000000010ed04d4f main + 111 
21 libdyld.dylib      0x0000000115e6968d start + 1 
22 ???         0x0000000000000001 0x0 + 1 
) 
libc++abi.dylib: terminating with uncaught exception of type NSException 

Answer 1

尝试改变：

let container = NSPersistentContainer(name: "DELETE") 

to this this ：

let container = NSPersistentContainer(name: "StudyHub") 

根据documentation：

默认情况下，提供的名称值被用来命名的持久性存储和使用来查找NSManagedObjectModel对象的名称与NSPersistentContainer使用目的。

Answer 2

我有类似的问题。我进入App Delegate，发现let container = NSPersistentContainer(name: "Your App Name")与我的数据模型的名称不匹配。

我将其更改为我的数据模型的名称，现在可以使用。