与此上下文的 CoreData SwiftUI 错误不同的 NSManagedObjectModel

Posted 2023-02-24

【中文标题】与此上下文的 CoreData SwiftUI 错误不同的 NSManagedObjectModel

【英文标题】：different NSManagedObjectModel than this context's' CoreData SwiftUI error

【发布时间】：2021-04-01 07:41:58

【问题描述】：

我之前刚刚为我的应用程序设置了 CoreData 来存储一些数据。我最初让它与不同的实体一起工作，但很快意识到它是错误的模型，并创建了一个新实体并删除了最初的实体。在我的 CoreDataManager 类中更改适当的变量/对象名称后，我一直遇到以下错误（线程问题）

'The fetch request's entity 0x600001040370 'UserSettings' appears to be from a different NSManagedObjectModel than this context's'
terminating with uncaught exception of type NSException

在这里给出一些上下文是我的 coreDataManager 类：

import Foundation
import UIKit
import CoreData

class CoreDataManager 
    
    static let shared: CoreDataManager = 
        let appDelegate = AppDelegate.instance!
        let instance = CoreDataManager(managedObjectContext: appDelegate.persistanceContainer.viewContext)
        return instance
    ()
    
    var managedContext: NSManagedObjectContext
    
    init(managedObjectContext: NSManagedObjectContext) 
        managedContext = managedObjectContext
    


//MARK:- CalorieTracker Insert/Update/Delete
extension CoreDataManager 
    func addUserSettingsData(id: UUID, firstName: String, height: Double, weight: Double, gender: String, age: Double, activityLevel: String, bmr: Double, completionHandler: @escaping (_ succeed: Bool, _ error: Error?) -> Void) 
        let userSettingsEntity = NSEntityDescription.insertNewObject(forEntityName: "UserSettings", into: managedContext) as? UserSettings
        userSettingsEntity?.id = id
        userSettingsEntity?.firstName = firstName
        userSettingsEntity?.height = height
        userSettingsEntity?.weight = weight
        userSettingsEntity?.gender = gender
        userSettingsEntity?.age = age
        userSettingsEntity?.activityLevel = activityLevel
        userSettingsEntity?.bmr = bmr
        
        do 
            try managedContext.save()
            completionHandler(true, nil)
         catch let error 
            completionHandler(false, error)
        
    
    
    func fetchCalorieTrackerData(completionHandler: @escaping (_ succeed: Any?, _ error: Error?) -> Void) 
        var progresses = [UserSettings]()
        let progressRequest: NSFetchRequest<UserSettings> = NSFetchRequest<UserSettings>(entityName: "UserSettings")
        
        do 
            progresses = try managedContext.fetch(progressRequest)
            completionHandler(progresses, nil)
         catch let error 
            completionHandler(nil, error)
        
    

我认为问题出在我的 fetch 请求中，因为在我的 viewModel 中创建实体时会执行 print 语句：

import Foundation

class AddViewModel: ObservableObject 
    
    @Published var userSettings = [UserSettings]()

    
    init() 
       fetchProgresses()
    
    
    //Creating the data
    func addCalorieTrackerDate(id: UUID, firstName: String, height: Double, weight: Double, gender: String, age: Double, activityLevel: String, bmr: Double) 
        CoreDataManager.shared.addUserSettingsData(id: id, firstName: firstName, height: height, weight: weight, gender: gender, age: age, activityLevel: activityLevel, bmr: bmr)  (isAdded, error) in
            if let error = error 
                print(error)
             else 
                print("Data has been added!")
                print(gender)
            
        
    
    
    //fetching the data
    func fetchProgresses() 
        CoreDataManager.shared.fetchCalorieTrackerData  (userSettings, error) in
            if let error = error 
                print(error)
            
            if let userSettings = userSettings as? [UserSettings] 
                self.userSettings = userSettings
            
        
    

我已经被这个错误困住了很长一段时间，任何帮助将不胜感激！

【问题讨论】：

您应该在 CoreDataManager 中将 init 方法设为私有，这样您就不会错误地创建单独的实例。

【参考方案1】：

我的程序的问题是在我的持久性文件中我使用了错误的名称。我没有使用 CoreData 类，而是使用了项目名称。正确的是：

container = NSPersistentContainer(name: "CalorieTracker")