Ios 非-Swift时解析用户名出错

我有一个相当大的两难选择。我的应用程序正在最新的parse sdk 1.1.12上运行。它会定期告诉新注册用户，用户名已被使用，但实际情况并非如此。我的注册分为三个独立的控制器，每个屏幕都有一个控制器，我将以前的注册信息传递到出现

signUpInBackgroundWithBlock

的最后一个控制器

我猜我在注册前是在操纵用户名吧？我把它转换成小写。大多数时候，注册确实有效，这是一个我无法理解的边缘案例。它抛出error.code 202，这是用户名获取的，但我保证在错误发生时不会获取它

它仍然注册用户，并成功地存储在数据库中。当用户在警报中点击OK时，我显示它要么将他们带入应用程序，要么他们终止应用程序并重新打开。当他们重新打开应用程序时，就会进入主屏幕

以下是我的片段：

 func parseSignUpUser() {
 // creating the new user
 self.showHudWithTitle("Signing Up...")

 user.username = self.email!.lowercaseString
 user.password = self.password
 user.email = self.email!
 user["fullName"] = self.firstName!+" " + self.lastName!
 user["University"] = self.universityName
 user["Sex"] = self.gender
 user["Age"] = NSNumber.init(long: ageNow!)

 // If user seleceted a profile image save it
 if (self.profileImageVw.image != nil) {
  let profileData = UIImageJPEGRepresentation(self.profileImageVw.image!, 0.5)
  let profileFile = PFFile(name: "profilePicture.png", data: profileData!)
  let thumbnailData = self.profileImageVw.image ? .resizeImage()
  let thumbnailFile = PFFile(name: "thumbnailPicture.png", data: thumbnailData!)
  user["profilePicture"] = profileFile
  user["thumbnailImage"] = thumbnailFile

  let myImageName = "profile.png"
  let imagePath = DBAccessManager.sharedInstance.fileInDocumentsDirectory(myImageName)
  self.saveImage(UIImage(data: thumbnailData!) !, path: imagePath)

 }
 user.signUpInBackgroundWithBlock {
   (succeeded: Bool, signUpError: NSError ? ) -> Void in

    if signUpError == nil {
      //successfully sign up the user 
   } else {
     //If email has been used for another account kPFErrorUserEmailTaken
    if (signUpError!.code == 202) {
     appDelegate.log.info("Error Code 202: Email Taken")

     let alertController = UIAlertController(title: "Sign Up Failed", message: "Sorry! Email has been taken! ", preferredStyle: .Alert)
     appDelegate.log.error("Error on 202")

     let OKAction = UIAlertAction(title: "OK", style: .Default) {
      (action) in
      // ...
     }
     alertController.addAction(OKAction)

     MBProgressHUD.hideAllHUDsForView(self.view, animated: true)

     self.presentViewController(alertController, animated: true) {
      // ...
     }
    }    
    else if (signUpError!.code == 203) {
     //If email has been used for another account kPFErrorUserEmailTaken                       ...
    } else if (self.profileImageVw.image == nil) {
     // If the user does not have an image show alert 
     ...
    } else {
     // all other cases show alert 
     ...
    } 
   }
  } // end of parseSignUpUser()
}

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你确定你的应用在注册时只调用parseSignUpUser（）一次吗？如果这个方法被调用了两次，那么其中一个会在另一个之前竞争，第二个会说用户名已经存在。是的，它只被调用了一次，问题是它偶尔会出现，当它说用户名不存在时，大多数人都注册了。