Question

单击“注册”按钮后，该应用程序应运行一个功能，在其中检查用户输入的用户名是否已被使用。如果是这样，它将停止“创建帐户”过程，告诉用户输入另一个用户名。

但是，输入相同的用户名并单击“注册”按钮后，它使我的应用程序崩溃，并显示Thread 1: signal SIGABRT错误。错误行注释如下。

如果有人可以帮助我，将不胜感激。

数据库JSON文件：

{
  "usernames" : {
    "itsandyjiang" : "0vFQYnfIbahHdC1RsuNMW45HYNR2"
  },
  "users" : {
    "0vFQYnfIbahHdC1RsuNMW45HYNR2" : {
      "email" : "andyjiang55@yahoo.com",
      "username" : "itsandyjiang"
    }
  }
}

检查用户是否输入了未使用的用户名的功能：

 func isValidUsername(username: String) {
        let usernameRegex = ".{3,}"
        var valid = NSPredicate(format: "SELF MATCHES %@", usernameRegex).evaluate(with: username)

        if valid {
            valid = !username.contains("Invalid username id")
        }

        if valid == false {


            usernameLabel.textColor = UIColor.red
            usernameLabel.text = "USERNAME MUST BE AT LEAST 3 CHARS"
            usernameTextField.layer.addBorder(edge: UIRectEdge.bottom, color: UIColor.red, thickness: 1.5)

        } else {

            let ref = Database.database().reference(fromURL: "https://testapp-testtest.firebaseio.com/")
            let usernamesRef = ref.child("usernames")

            usernamesRef.observeSingleEvent(of: .value, with: { (snapshot) in
                let usernamesArray = Array(snapshot.value as! [String]) //ERROR LINE
                for storedUsername in usernamesArray {
                    if storedUsername == self.usernameTextField.text! {
                        self.usernameVerified = false
                        self.usernameLabel.textColor = UIColor.red
                        self.usernameLabel.text = "USERNAME TAKEN"
                        self.usernameTextField.layer.addBorder(edge: UIRectEdge.bottom, color: UIColor.red, thickness: 1.5)
                        return
                    }
                }
                self.usernameVerified = true
                self.usernameTextField.layer.addBorder(edge: UIRectEdge.bottom, color: UIColor.black, thickness: 1.5)
                self.usernameLabel.textColor = UIColor.black
                self.usernameLabel.text = "USERNAME"

            }) { (error) in
                print(error.localizedDescription)
            }

        }
    }

单击“登录”按钮后运行的功能：

   @IBAction func onSignUp(_ sender: Any) {

        isValidUsername(username: usernameTextField.text!)
        isValidEmail(email: emailTextField.text!)
        isValidPassword(password: passwordTextField.text!)

        if passwordVerified && emailVerified && usernameVerified {

            Auth.auth().createUser(withEmail: emailTextField.text!, password: passwordTextField.text!) { (authResult, error) in
                if error != nil {
                    self.errorLabel.alpha = 1
                    self.errorLabel.text = error?.localizedDescription
                }

                guard let user = authResult?.user else {
                    return
                }


                //Successfully Authenticated User
                let ref = Database.database().reference(fromURL: "https://testapp-testtest.firebaseio.com/")
                let usersReference = ref.child("users").child(user.uid)
                let values = ["username": self.usernameTextField.text, "email": self.emailTextField.text]
                let usernamesReference = ref.child("usernames")
                let values2 = [self.usernameTextField.text!: user.uid]
                usersReference.updateChildValues(values, withCompletionBlock: { (err, ref) in
                    if err != nil {
                        print(err!)
                        return
                    }
                    //Successfully registered user's data to database
                    usernamesReference.updateChildValues(values2, withCompletionBlock: { (err, ref) in
                        if err != nil {
                            print(err!)
                            return
                        }

                        self.errorLabel.alpha = 0

                    })

                })
            }

        } else {

            errorLabel.alpha = 1
            print("Password/Email/Username verification not complete!")

        }

    }

Answer 1

您需要将其转换为字典，因为所附的json暗示了

 let con = snapshot.value as! [String:Any]
 let usernamesArray =  Array(con.keys)

您当前的方案中也有重复项，因此请考虑将所有用户数据设置在1个表中，不要将它们分开，也许仅仅是这样

{ 
  "users" : {
    "0vFQYnfIbahHdC1RsuNMW45HYNR2" : {
      "email" : "andyjiang55@yahoo.com",
      "username" : "itsandyjiang"
    }
  }
}

然后

   let ref = Database.database().reference(fromURL: "https://testapp-testtest.firebaseio.com/")
   let usernamesRef = ref.child("users")

      usernamesRef.observeSingleEvent(of: .value, with: { (snapshot) in
      let con = snapshot.value as! [String:[String:Any]]
      var usernamesArray = [String]()
      Array(con.keys).forEach {
         if let res = con[$0] , let username = res["username"] as? String {
           usernamesArray.append(username)
         }
      }
      // after that check whether exists / not 

  ---

防止重复的用户名导致线程1：信号SIGABRT

1 个答案: