Swift 2.0 - 「傳遞給調用的參數不需要參數」

Question

我檢查了與此問題相關的所有其他線程，但似乎沒有任何工作。在這段代碼中，我得到就行了一個錯誤 「如果moc.hasChanges ...」：

func saveContext() { 
    var error: NSError? = nil 

    if let moc = self.managedObjectContext { 

     if moc.hasChanges && !moc.save(error) { 
      // Replace this implementation with code to handle the error appropriately. 
      // abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. 
      NSLog("Unresolved error \(error), \(error!.userInfo)") 
      abort() 
     } 
    } 

} 

以下是完整的.swift文件：

import UIKit 
import CoreData 

@UIApplicationMain 
class AppDelegate: UIResponder, UIApplicationDelegate { 

var window: UIWindow? 

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool { 
    // Override point for customization after application launch. 

    UIApplication.sharedApplication().setStatusBarStyle(UIStatusBarStyle.LightContent, animated: true) 

    return true 
} 

func applicationWillResignActive(application: UIApplication) { 
    // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state. 
    // Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game. 
} 

func applicationDidEnterBackground(application: UIApplication) { 
    // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later. 
    // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits. 
} 

func applicationWillEnterForeground(application: UIApplication) { 
    // Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background. 
} 

func applicationDidBecomeActive(application: UIApplication) { 
    // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface. 
} 

func applicationWillTerminate(application: UIApplication) { 
    // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:. 
    // Saves changes in the application's managed object context before the application terminates. 
    //self.saveContext() 
} 

// MARK: - Core Data stack 

lazy var applicationDocumentsDirectory: NSURL = { 
    // The directory the application uses to store the Core Data store file. This code uses a directory named "HardingSoftware.HRC" in the application's documents Application Support directory. 
    let urls = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask) 
    return urls[urls.count-1] 
}() 

lazy var managedObjectModel: NSManagedObjectModel = { 
    // The managed object model for the application. This property is not optional. It is a fatal error for the application not to be able to find and load its model. 
    let modelURL = NSBundle.mainBundle().URLForResource("HRC", withExtension: "momd")! 
    return NSManagedObjectModel(contentsOfURL: modelURL)! 
}() 

lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator? = { 
    // The persistent store coordinator for the application. This implementation creates and return a coordinator, having added the store for the application to it. This property is optional since there are legitimate error conditions that could cause the creation of the store to fail. 
    // Create the coordinator and store 
    var coordinator: NSPersistentStoreCoordinator? = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel) 
    let url = self.applicationDocumentsDirectory.URLByAppendingPathComponent("HRC.sqlite") 
    var error: NSError? = nil 
    var failureReason = "There was an error creating or loading the application's saved data." 
    coordinator = nil 

    do { 

    try coordinator!.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: url, options: nil) 
    } catch { 
     // Report any error we got. 
     var dict = [String: AnyObject]() 
     dict[NSLocalizedDescriptionKey] = "Failed to initialize the application's saved data" 
     dict[NSLocalizedFailureReasonErrorKey] = failureReason 
     dict[NSUnderlyingErrorKey] = error as NSError 
     let wrappedError = NSError(domain: "YOUR_ERROR_DOMAIN", code: 9999, userInfo: dict) 
     // Replace this with code to handle the error appropriately. 
     // abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. 
     NSLog("Unresolved error \(wrappedError), \(wrappedError.userInfo)") 
     abort() 
    } 

    return coordinator 
}() 

lazy var managedObjectContext: NSManagedObjectContext? = { 
    // Returns the managed object context for the application (which is already bound to the persistent store coordinator for the application.) This property is optional since there are legitimate error conditions that could cause the creation of the context to fail. 
    let coordinator = self.persistentStoreCoordinator 
    if coordinator == nil { 
     return nil 
    } 
    var managedObjectContext = NSManagedObjectContext() 
    managedObjectContext.persistentStoreCoordinator = coordinator 
    return managedObjectContext 
}() 

// MARK: - Core Data Saving support 

func saveContext() { 
    var error: NSError? = nil 

    if let moc = self.managedObjectContext { 

     if moc.hasChanges && !moc.save(error) { 
      // Replace this implementation with code to handle the error appropriately. 
      // abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. 
      NSLog("Unresolved error \(error), \(error!.userInfo)") 
      abort() 
     } 
    } 

} 

}

Answer 1

在雨燕2.0，保存上下文，你必須使用do { try ...}和catch {...}您的錯誤。

do { 
    try context.save() 
} catch let error { 
    print("Could not cache the response \(error)") 
} 

你的情況：

func saveContext() { 
var error: NSError? = nil 

if let moc = self.managedObjectContext { 

    if moc.hasChanges { 

     do { 
      try moc.save() 
     } catch let error { 
      print("Could not cache the response \(error)") 
     } 
    } 
} 
} 

Answer 2

的NSManagedObjectContext現在有一個保存功能，不再使用錯誤參數。相反，您必須捕獲try-catch塊中的錯誤。

do { try context.save() } 
catch let error { print((error as NSError)) }