Swift 3 RKObjectRequestOperation 返回错误无法转换类型为 RKObjectRequestOperation

Question

我正在尝试将代码从现有应用程序转换为 swift 3 (Xcode 8.1)，但我卡在下面给出错误的代码上：

cannot convert value of type (RKObjectRequestOperation!, RKMappingResult!) -> Void to expected argument type (RKObjectRequestOperation?, RKMappingResult?) -> Void!) 

这是我的代码：

class func getShoppingItemsForPage(_ page: Int,pageSize: Int,
                                       completionHandler:@escaping ([ShopItemModel]?,NSError?) -> ()) {

        RKObjectManager.sharedManager().getObjectsAtPath("search",
                    parameters: ["page" : page, "pagesize" : pageSize], success: { (request: RKObjectRequestOperation!, result: RKMappingResult!) -> Void in

                let resultArray = result.array() as? [ShopItemModel]
                completionHandler(resultArray,nil)

            }) { (request: RKObjectRequestOperation!, error: NSError!) -> Void in

                completionHandler(nil,error)
        }
    }

我怀疑这可能与我看到的 FBSDKLoginManager 中的类似错误有关

Cannot convert value of type (FBSDKLoginManagerLoginResult!, NSError!) -> Void to expected argument type "FBSDKLoginManagerRequestTokenHandler!"

这是产生错误的 Facebook 代码。

loginManager.logIn(withReadPermissions: facebookReadPermissions, from: self, handler: {(result:FBSDKLoginManagerLoginResult!,error:NSError!) -> Void in
            if error != nil {
                // Process Error
            }
            else if result.isCancelled {
                // Cancelled by User
            }
            else {
                let delegate:AppDelegate = UIApplication.shared.delegate as! AppDelegate
                delegate.showMainStoryboard()
            }
        })

Answer 1

class func getShoppingItemsForPage(_ page: Int,pageSize: Int,
                                      completionHandler:@escaping ([ShopItemModel]?,NSError?) -> ()) {

      RKObjectManager.sharedManager().getObjectsAtPath("search",
                                                       parameters: ["page" : page, "pagesize" : pageSize],
                                                       success: {(operation: RKObjectRequestOperation!, mappingResult: RKMappingResult!) -> Void in
                                                         let resultArray = mappingResult.array() as? [ShopItemModel]
                                                         completionHandler(resultArray,nil)
      }, failure: {(operation: RKObjectRequestOperation!, error: NSError!) -> Void in
         completionHandler(nil,error)
      })
   }

Answer 2

解决方案是将错误类型从 NSError 更改为 Error，并使调用和结果参数可选。