类的NSManagedObject＆＃39; Grapevine_2017.SearchEntity＆＃39;必须具有有效的NSEntityDescription

Question

收到错误 - 类的一个NSManagedObject＆＃39; Grapevine_2017。SearchEntity＆＃39;必须有一个有效的NSEntityDescription

我已经查看了所有其他堆栈流量解决方案，仍然无法解决它。

我的数据模型的名称是Grapevine_2017.xcdatamodeld

这是我的代码

import Foundation
import CoreData

class persistenceService {

// MARK: - Core Data stack


private init() {}

static var context: NSManagedObjectContext {
    return persistentContainer.viewContext
}

static var persistentContainer: NSPersistentContainer = {

    let container = NSPersistentContainer(name: "Grapevine_2017")
    container.loadPersistentStores(completionHandler: { (storeDescription, error) in
        if let error = error as NSError? {


            fatalError("Unresolved error \(error), \(error.userInfo)")
        }
    })
    return container
}()

// MARK: - Core Data Saving support

static func saveContext () {
    let context = persistentContainer.viewContext
    if context.hasChanges {
        do {
            try context.save()
        } catch {


            let nserror = error as NSError
            fatalError("Unresolved error \(nserror), \(nserror.userInfo)")
        }
    }
}
}



 public class SearchEntity: NSManagedObject {

}


 extension SearchEntity {

@nonobjc public class func fetchRequest() -> NSFetchRequest<SearchEntity> {
    return NSFetchRequest<SearchEntity>(entityName: "SearchEntity")
    }

@NSManaged public var distance: String?

 }