错误没有初始化所有存储的特性从初始返回

Question

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我迅速转换1.2到3.2迅速这里init的示值误差任何宝贵意见普莱舍

var context:NSManagedObjectContext 
var psc:NSPersistentStoreCoordinator 
var model:NSManagedObjectModel 
var store:NSPersistentStore? = nil 
var contextDict = [Int : NSManagedObjectContext]() 
var results:NSBatchUpdateResult 

init() { 
    let bundle = Bundle.main 
    let modelURL = 
    bundle.url(forResource: "maildough", withExtension:"momd") 
    model = NSManagedObjectModel(contentsOf: modelURL!)! 
    psc = NSPersistentStoreCoordinator(managedObjectModel:model) 
    context = NSManagedObjectContext(concurrencyType:.mainQueueConcurrencyType) 
    context.persistentStoreCoordinator = psc 
} ///getting error here 

给错误从初始retrun没有初始化所有存储性能

Answer 1

那你需要如何做它迅速3+ ​​

var errorHandler: (Error) -> Void = {_ in } 

lazy var libraryDirectory: NSURL = { 

    let urls = FileManager.default.urls(for: .libraryDirectory, in: .userDomainMask) 

    return urls[urls.count-1] as NSURL 
}() 


lazy var managedObjectModel: NSManagedObjectModel = { 

    let modelURL = Bundle.main.url(forResource: "maildough", withExtension: "mom") 
    return NSManagedObjectModel(contentsOf: modelURL!)! 
}() 


lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator = { 
    let coordinator = NSPersistentStoreCoordinator(managedObjectModel: 
     self.managedObjectModel) 
    let url = 
self.libraryDirectory.appendingPathComponent("maildough.sqlite") 
    do { 
     try coordinator.addPersistentStore(ofType: 
      NSSQLiteStoreType, 
              configurationName: nil, 
              at: url, 
              options: [ 
              NSMigratePersistentStoresAutomaticallyOption: true, 

NSInferMappingModelAutomaticallyOption: true 
      ] 
     ) 
    } catch { 
     // Report any error we got. 
     NSLog("CoreData error \(error), \(error._userInfo)") 
     self.errorHandler(error) 
    } 
    return coordinator 
}() 

lazy var managedObjectContext: NSManagedObjectContext = { 
    let coordinator = self.persistentStoreCoordinator 
    var mainManagedObjectContext = NSManagedObjectContext(concurrencyType: .mainQueueConcurrencyType) 
    mainManagedObjectContext.persistentStoreCoordinator = coordinator 
    return mainManagedObjectContext 
}()