我需要执行一系列http请求并将结果保存在CoreData中。我还需要能够相应地背景应用程序，任务必须继续。我尝试在 UIApplication.shared.beginBackgroundTask 和 UIApplication.shared.endBackgroundTask 之间附加任务，但在这种情况下，保存到CoreData不正确或不会发生（错误） 。 如何正确实现？
首先，我做了很多请求，然后在最后我调用saveContext并期望完成。我有跟随线，它在前台工作。
上下文：
context = CoreDataManager.instance.persistentContainer.newBackgroundContext()
CoreDataManager ：
class CoreDataManager {
static let instance = CoreDataManager()
private init() {}
@available(iOS 10.0, *)
lazy var persistentContainer: NSPersistentContainer = {
let container = NSPersistentContainer(name: "Addresses")
container.loadPersistentStores(completionHandler: { (storeDescription, error) in
if let error = error {
fatalError("Unresolved error \(error)")
}
})
return container
}()
func getContext () -> NSManagedObjectContext {
var context: NSManagedObjectContext?
if #available(iOS 10.0, *) {
context = persistentContainer.viewContext
} else {
guard let modelURL = Bundle.main.url(forResource: "Addresses", withExtension:"momd") else {
fatalError("Error loading model from bundle")
}
guard let mom = NSManagedObjectModel(contentsOf: modelURL) else {
fatalError("Error initializing mom from: \(modelURL)")
}
let psc = NSPersistentStoreCoordinator(managedObjectModel: mom)
let urls = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
let docURL = urls[urls.endIndex-1]
let storeURL = docURL.appendingPathComponent("Addresses.sqlite")
do {
try psc.addPersistentStore(ofType: NSSQLiteStoreType, configurationName: nil, at: storeURL, options: nil)
} catch {
fatalError("Error migrating store: \(error)")
}
context = NSManagedObjectContext(concurrencyType: .privateQueueConcurrencyType)
context?.persistentStoreCoordinator = psc
}
return context!
}
func saveContext(context: NSManagedObjectContext){
if (context.hasChanges){
context.performAndWait {
do {
try context.save()
} catch let error as NSError {
print("Could not save \(error), \(error.userInfo)")
}
}
}
}
}
简单请求：
NetworkManager.sharedInstance.request(url).responseJSON(queue: queue){ response in
if (response.error == nil){
let jsonDataImage: Data = response.data!
do{
if let jsonResultImage = try JSONSerialization.jsonObject(with: jsonDataImage, options: []) as? [String:AnyObject] {
if (jsonResultImage["Status"] as! Int==0){
let tasks = Tasks(context: context)
let str = (jsonResultImage["task"] as! String)
if let data = NSData(base64Encoded: str, options:NSData.Base64DecodingOptions.init(rawValue: 0)){
tasks.image = data
}
tasks.id = taskId
tasks.name = (taskArray![j]["Custom"] as! NSString) as String
tasks.place = (taskArray![j]["Place_ar"] as! NSString) as String
tasks.shemeId = taskArray![j]["ShemeId"] as! Int32
}
}
}catch{
print(error)
}
}
}
我离开 URLSessionConfiguration.default 和变量 queue - .utility （还）。