此应用程序正在从后台线程修改autolayout引擎,这可能导致引擎损坏

Question

我收到此错误此应用程序正在从后台线程修改autolayout引擎,这可能导致引擎损坏和奇怪的崩溃.这将导致未来版本中的异常.我不知道是什么导致了这个错误.有谁能够帮我.

func getUserDataFromTwitterWithUser(user : PFUser)
 {
//NRLoader.showLoader()
let strTwURL = "https://api.twitter.com/1.1/users/show.json?     screen_name="+PFTwitterUtils.twitter()!.screenName! + "&access_token="+PFTwitterUtils.twitter()!.authToken!
let twURL = NSURL (string: strTwURL)

let request = NSMutableURLRequest(URL: twURL!, cachePolicy: NSURLRequestCachePolicy.UseProtocolCachePolicy, timeoutInterval: 2.0) as NSMutableURLRequest

PFTwitterUtils.twitter()?.signRequest(request)

let session = NSURLSession.sharedSession()

session.dataTaskWithRequest(request, completionHandler: {(data, response, error) in
  if error == nil {
    var  jsonOptional = Dictionary<String, AnyObject>()

    do {
      jsonOptional = try NSJSONSerialization.JSONObjectWithData(data!, options:NSJSONReadingOptions.MutableContainers ) as! Dictionary<String, AnyObject>
      // use jsonData
    } catch {
      // report error
    }
    var userName = ""
    if let screenName = jsonOptional["screen_name"] as? String{
      userName = screenName
    }
    else if let name = jsonOptional["name"] as? String{
      userName = name
    }

    var profilePicUrl = ""


    if let picUrl = jsonOptional["profile_image_url"] as? String{
      profilePicUrl = picUrl
    }
    AppUser.currentUser()?.username = userName
    AppUser.currentUser()?.profileAwsURL = profilePicUrl
    //NRLoader.hideLoader()
    //if ParseUtils.isLoggedInUserIsAnonymous() {
      let signUpVC:SignMeUpViewController = self.storyboard!.instantiateViewControllerWithIdentifier("SignMeUpViewController") as! SignMeUpViewController
      signUpVC.isFromLogin = true
      self.navigationController!.pushViewController(signUpVC, animated: true)

    //} else {
     // self.pushToSubmitDreamViewController()
    //}
  }
  else {
    //NRLoader.hideLoader()
    NRToast.showToastWithMessage(error!.description)
  }


}).resume()
 }

Answer 1

该dataTaskWithRequest呼叫在后台运行,然后调用在同一个线程的完成处理程序.更新UI的任何内容都应该在主线程上运行,因此所有当前的处理程序代码都应该在dispatch_async主队列的后面:

dispatch_async(dispatch_get_main_queue()) {
  // Do stuff to UI
}

斯威夫特3:

DispatchQueue.main.async() {
  // Do stuff to UI
}

因此,理想情况下,您当前拥有的所有代码都if error == nil应该在另一个函数中关闭,例如调用handleRequest,因此您当前的代码变为:

session.dataTaskWithRequest(request, completionHandler: {(data, response, error) in
    if error == nil {
        dispatch_async(dispatch_get_main_queue(), {
            self.handleRequest(...)I
        })
    }

Answer 2

斯威夫特3

session.dataTaskWithRequest(request, completionHandler: {(data, response, error) in
if error == nil {
    DispatchQueue.main.async {
        self.handleRequest(...)I
    }
}

Answer 3

应该尝试Symbolic Breakpoint来检测问题: -

然后将您的UI更新代码放在主线程中

DispatchQueue.main.async {}