夫特：弱引用的存儲＆嵌套塊/閉合

Question

我想找嵌套的塊/閉合，而另一個過程完成關閉主線程的，像這樣

typealias FirstBlock = (jsonDictionary:NSDictionary?,errorCode:NSString?) -> Void 

typealias SecondBlock = (complete:Bool?,errorCode:NSString?,dictionary:NSDictionary?) -> Void 

• 控制器

  func startPoint { 
  
       SomeNetworkManager.sharedInstance.firstProcess(self.someDictionary) { (complete, errorCode, dictionary) -> Void in 
  
       // I want to get here with a strong reference to these objects in this class only 
       print(complete,errorCode,dictionary) 
      } 
  } 
  

• SomeNetworkManager

  func firstProcess(dictionary:NSDictionary?, completion:SecondBlock?) { 
  
  let request = HTTPRequest.init(requestWithPath:"path", httpMethod: .post) { (jsonDictionary, errorCode) -> Void in 
  
      let organisedDictionary:NSMutableDictionary = NSMutableDictionary() 
      // Some processing of the json into a new dictionary 
  
      dispatch_async(dispatch_get_main_queue()) { 
  
       if errorCode == nil { 
  
        completion!(complete:true,errorCode:nil,dictionary:organisedDictionary) 
       } 
       else { 
  
        completion!(complete:false,errorCode:errorCode,dictionary:nil) 
       } 
      } 
  } 
  
  request.postDataDictionary = refinementsDictionary as! NSMutableDictionary 
  request.request() 
  
  } 
  

• 的HTTPRequest

  var processBlock:FirstBlock? 
  
  init(requestWithPath path:NSString, httpMethod method:HTTPMethod, andProcessBlock block:FirstBlock) { 
  
      super.init() 
  
      self.requestURL = NSURL(string:path as String); 
      self.responseData = NSMutableData() 
      self.processBlock = block 
  
      switch (method) { 
      case .post: 
       self.httpMethod = kPost 
       break; 
      case .put: 
       self.httpMethod = kPut 
       break; 
      default: 
       self.httpMethod = kGet 
       break; 
      } 
  
  } 
  
  // An NSURLConnection goes off, completes, I serialise the json and then... 
  
  func completeWithJSONDictionary(jsonDictionary:NSDictionary) { 
  
      self.processBlock!(jsonDictionary:jsonDictionary,errorCode:nil) 
      self.processBlock = nil 
  } 
  

我失去了一些東西根本就ARC保留週期，因爲每其中之一叫我得到了內存泄漏的時間..我看了一下 https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/AutomaticReferenceCounting.html 沒有喜悅..我認爲Defining a Capture List是正確的領域，但至於存儲塊和如何定義它，我不知道我做錯了什麼。

Answer 1

在所有的可能性，你要保留週期，因爲完成塊引用的HttpRequest（可能是通過調用對象），引用完成塊的，是這樣的：

class HttpReference { 
    let completion :()->() 

    init(completion:()->()) { 
     self.completion = completion 
    } 
} 

class Owner { 
    var httpReference : HttpReference? 

    func someFunction() { 
     httpReference = HttpReference() { 
      print(self.httpReference) 
     } 
    } 
} 

有兩種方法，打破循環，或者通過使用通過使用weak參考一個unowned引用或，兩者都是相當類似，在這種情況下，規範是通過改變使用無主參考自：

func someFunction() { 
    httpReference = HttpReference() { [unowned self] in 
     print(self.httpReference) 
    } 
} 

現在，不保留self，從而打破保留週期。