核心数据崩溃尝试使用 userInfo (null) 插入 nil

Question

当我的代码尝试从 API 下载系列时，它随机崩溃并显示以下错误消息：

（实体：系列；id：0x7b181002016-04-04 14:01:33.868 Postzegel Catalogus[1816:39059] CoreData：错误：严重的应用程序错误。在核心数据更改处理期间捕获异常。这通常是观察者中的错误NSManagedObjectContextObjectsDidChangeNotification .- [ NSCFSet addObject:]: 尝试用 userInfo (null) 0 (entity: Series; id: 0x7b00c450 ; 2016-04-04 14:01:33.871 Postzegel Catalogus[1816:39059] *** 终止应用程序插入 nil由于未捕获的异常 'NSInvalidArgumentException'，原因：'-[__NSCFSet addObject:]: 尝试插入 nil' *** 第一次抛出调用堆栈：( 0 CoreFoundation 0x0083d494 __exceptionPreprocess + 180 1 libobjc.A.dylib
0x02551e002throw objc
0x0083d3bd + [NSException提高：格式：] + 141 3的CoreFoundation
0x0070c959 - [__ NSCFSet ADDOBJECT：] + 185 4 CoreData
0x0038a010 - [的NSManagedObjectContext（_NSInternalChangeProcessing）_processPendingInsertions：withDeletions：withUpdates：] + 560 5 CoreData 0x003846da - [的NSManagedObjectContext（_NSInternalChangeProcessing）_processRecentChanges :] + 2410 6 CoreData 0x00383d56 -[NSManagedObjectContext processPendingChanges] + 54 7
CoreData 0x003ae5e4 -[NSManagedObjectContext(_NestedContextSupport) _parentProcessSaveRequest:inContext:error:] + 116 8 CoreData 0x00433bec __82-[NSManagedObjectContext(_NestedContextSupport) executeRequest:withContext:error:]_block_invoke9 + CoreData1
0x003a924c internalBlockToNSManagedObjectContextPerform + 76 10 libdispatch.dylib 0x03c8f9cd _dispatch_client_callout + 14 11 libdispatch.dylib 0x03c76d90 _dispatch_barrier_sync_f_slow_invoke + 133 12 libdispatch.dylib 0x03c8f9cd _dispatch_client_callout + 14 13 libdispatch.dylib 0x03c74f7c _dispatch_main_queue_callback_4CF + 910 14的CoreFoundation 0x007871be __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE + 14 15的CoreFoundation 0x00745434 __CFRunLoopRun + 2356 16的CoreFoundation 0x00744846 CFRunLoopRunSpecific + 470 17 CoreFoundation
0x0074465b CFRunLoopRunInMode + 123 18 GraphicsServices
0x07a8d664 GSEventRunModal + 192 19 GraphicsServices
0x07a8d4a1 GSEventRun + 104 20 UIKit
0x0102beb9 UIApplicationMain + 160 21 Postzegel Catalogus
0x000f63b1 主 + 10205c
1405c 145c idc 14505c idc

我只是不知道为什么？我使用了一个私有的托管上下文选项，以便使用 . 我什至将 .xcdatamodeld 中的字段设置为可选。所以它应该不是问题，它是零吗？它只是不断地随机崩溃，甚至不是在同一个对象上。我怎样才能解决这个问题？

我包含了我的代码，希望对您有所帮助。我已删除我的 API 密钥，因此您将无法试用。如果您对我的代码有任何其他评论，请告诉我，我是 Core Data 和 Alamofire 的新手，所以我有机会制作“意大利面代码”。

提前致谢

import Foundation
import CoreData
import Alamofire
import SwiftyJSON

//CoreData Init
let appDelegate: AppDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
let managedContext: NSManagedObjectContext = appDelegate.managedObjectContext

let queue = dispatch_queue_create("com.GJ-Computers.Postzegel-Catalogus.responseJSON-Manager", DISPATCH_QUEUE_CONCURRENT)

//Colnect API
let LANG: String = NSLocale.preferredLanguages()[0].substringToIndex(NSLocale.preferredLanguages()[0].startIndex.advancedBy(2))
let DATE = NSCalendar.currentCalendar().component([.Day, .Month, .Year], fromDate: NSDate())
let API_KEY: String = "----" //Private API KEY
let CAT_STAMPS: String = ("cat/stamps/")
var BASE_URL: String{
    return ("http://api.colnect.net/" + LANG + "/api/" + API_KEY + "/")
}

//Ghetto Delegate
var didGetCountires: Bool = false
var didGetYears: Bool = false
var didGetSeries: Bool = false

//MARK: - First Time setup Database
func setupDatabase(){
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)){


        getYears() //Download Years per country from database        
}
    }


//get Series
func getSeries(){
    //Retrieve Countries from Coredata
    let countryFetchRequest = NSFetchRequest(entityName: "Countries")
    var results: [Countries]?
    do {
        results = try managedContext.executeFetchRequest(countryFetchRequest) as? [Countries]
    } catch let error as NSError {
        print("Could not fetch \(error), \(error.userInfo)")
    }

    let resultCount = results!.count
    var completedRequestCount: Int = 0
    var requestedRequests = 0


    for result in results!{
        let countryID = result.countryID
        Alamofire.request(.GET, (BASE_URL + "series/"+CAT_STAMPS+"producer/\(countryID)")).responseJSON(queue: queue, completionHandler:{ response in
            if let json = response.result.value{
                let privateMOC = NSManagedObjectContext(concurrencyType: .PrivateQueueConcurrencyType)
                privateMOC.parentContext = managedContext

                let rawData = JSON(json)
                for data in rawData {
                    //Setup let
                    let seriesID = Int(data.1.array![0].string!)
                    let seriesName = data.1.array![1].string
                    let itemCount = Int(data.1.array![2].string!)

                    if seriesID != 0 && itemCount != 0 && seriesName != nil{
                        privateMOC.performBlock{
                            let series = NSEntityDescription.insertNewObjectForEntityForName("Series", inManagedObjectContext: managedContext) as! Series
                            series.countryID = countryID
                            series.seriesID = seriesID
                            series.seriesName = seriesName
                            series.itemCount = itemCount

                            print(completedRequestCount)

                            do {
                                try privateMOC.save()
                            } catch let error as NSError  {
                                print("Could not save \(error), \(error.userInfo)")
                            }
                        }

                    }else{
                        print("ERROR")
                    }

                }
            }
            completedRequestCount += 1
            print(completedRequestCount)
        })
        requestedRequests += 1
        if(requestedRequests == resultCount){
            dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)){
                while(true){
                    if(completedRequestCount == resultCount){
                        didGetSeries = true
                        sleep(3)
                        print("DEBUG - Series Done")
                        break
                    }
                }
            }
        }
    }
}

Answer 1

其实，使用私有 MOC 解决了你的问题的原因是因为你是在后台线程中执行操作，而当你在后台线程中进行 coredata 操作时，你必须确保

• 托管对象上下文绑定到它们在初始化时关联的线程（队列）
• 从上下文检索的托管对象绑定到上下文绑定到的同一队列

仅供参考，不是因为（“我制作了一个私有 MOC，但是当你制作一个时，你必须始终将它添加到代码中，否则它将无法工作。我忘了用 privateMOC 替换 managedContext”）