swift - 将 firebase 数据库值转换为 Int

Question

在我的应用程序中，人们可以对他们认为会获胜的球队下注。当他们去打赌时，应该将一些东西上传到数据库中。首先是下注者的用户名。这是哪个投注(是一注二注三)，它应该显示投注的球队。

问题 我将赌注转换为 Int，这样每次有人下注时我都可以递增它，这样他们就有了唯一的赌注。

下面我要解释几件事，因为出于测试目的，我的代码现在很困惑。

在 viewDidLoad 方法中，我可以收集用户名和某人下注的次数。在数据库中，这默认为字符串“0”。

现在下注 self.betNumber 的值应该是“0”

然后在 submitData 函数中，我安全地获取 betNumber 并将其转换为 Int，然后将该值分配给全局声明的变量 bets

然后我将赌注增加 1之后我尝试将 self.bets 转换成一个字符串，但它作为一个 child 进入数据库

这是我遇到错误的地方

import UIKit
import Foundation
import Firebase


class addBets: UIViewController {
    let betRef = FIRDatabase.database().reference(fromURL: "not showing these sorry")
    let userRef = FIRDatabase.database().reference(fromURL: "")
    let ref = FIRDatabase.database().reference(fromURL: "")
    let currentUser = FIRAuth.auth()?.currentUser


    @IBOutlet weak var teamOneLabelAdd: UILabel!
    @IBOutlet weak var teamTwoLabelAdd: UILabel!

    @IBOutlet weak var teamOneBet: UITextField!

    @IBOutlet weak var teamTwoBet: UITextField!



    var userName: String!
    var teamOne: String!
    var teamTwo = String()

    var betNumber: String!
    var bets: Int = 0




    var teamOneBetAnotherOne: String!
    var teamOneBetAnotherTwo: String!
    override func viewDidLoad() {
        super.viewDidLoad()
        teamOneLabelAdd.text = teamOne
        teamTwoLabelAdd.text = teamTwo


        //Looks for single or multiple taps.
        let tap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: "dismissKeyboard")

        //Uncomment the line below if you want the tap not not interfere and cancel other interactions.
        tap.cancelsTouchesInView = false

        view.addGestureRecognizer(tap)

        //self.teamOneBet.delegate = self
        //self.teamTwoBet.delegate = self

        let userID = FIRAuth.auth()?.currentUser?.uid
        ref.child("User").child(userID!).observeSingleEvent(of: .value, with: { (snapshot) in
            // Get user value
            let value = snapshot.value as? NSDictionary
            let username = value?["username"] as? String ?? ""
            self.userName = username
            let betnumber = value?["bets"] as? String ?? ""
            self.betNumber = betnumber




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


    }

    func textFieldShouldReturn(userText: UITextField!) -> Bool {
        teamOneBet.resignFirstResponder()
        teamTwoBet.resignFirstResponder()
        return true
    }


    func dismissKeyboard() {
        //Causes the view (or one of its embedded text fields) to resign the first responder status.
        view.endEditing(true)
    }

    @IBAction func submitData(_ sender: Any) {
        // get the userName to tell who is doing the bet and set it as a key

        sleep(4)

        if let usernamee = self.userName {
            if let anotherBet = self.betNumber as? Int {
                self.bets = anotherBet
            }
            self.bets += 1

            let usableBets = self.bets as? String ?? ""

            let useRef = self.ref.child("Bets").child(usernamee).child(self.bets as? String ?? "")

            var values = ["Username": usernamee,"Bet": "0", "ForTeam": ""]
            if let betOne = self.teamOneBet.text{

                if betOne == "" {

                } else {
                    values["Bet"] = betOne
                    values["ForTeam"] = teamOneLabelAdd.text
                }
            }
            if let betTwo = self.teamTwoBet.text{

                if betTwo == "" {

                } else {
                    values["Bet"] = betTwo
                    values["ForTeam"] = teamTwoLabelAdd.text
                }
            }


        //self.betRef.child("Bets").setValue(self.userName)
        if let worked = currentUser?.getTokenWithCompletion() {

            useRef.setValue(values)
            /*
            useRef.updateChildValues(values, withCompletionBlock: { (error, ref) in
                if (error != nil) {
                    print(error!)
                    return

                }

            })
            */



        }


         self.navigationController?.popViewController(animated: true)

        }







    }

    func getUserName() {
        let userID = FIRAuth.auth()?.currentUser?.uid
        ref.child("User").child(userID!).observeSingleEvent(of: .value, with: { (snapshot) in
            // Get user value
            let value = snapshot.value as? NSDictionary
            let username = value?["username"] as? String ?? ""
            self.userName = username

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


    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        //let indexPath = self.tableView.indexPathForSelectedRow!
        //var DestViewController : addBets = segue.destination as! addBets
        //DestViewController.teamOne = self.teamOne.text!
        //DestViewController.teamOne = self.teamTTwo

        if segue.identifier == "gotobetview" {
            if let destination = segue.destination as? BetView {

                //destination.userNames = self.teamOne.text! as? String

                //destination.teamTwo = (self.teamTwo.text! as? String)!
            }
        }

    }

}

这里是 firebase 结构，我提取的数据来自“用户”，我写入的数据是“赌注”

Answer 1

粗略地看一下您的代码，错误似乎在这一行:

let useRef = self.ref.child("Bets").child(usernamee).child(self.bets as? String ?? "")

我不完全确定您想在哪里发布用户的投注，但这样做是将 useRef 设置为位于 Bets.\(usernamee) 的 child 。 1 下注为 1 时为 Bets.\(usernamee).2 下注为 2 等

如果您希望每次下注都是唯一的，只需将 useRef 更改为:

let useRef = self.ref.child("Bets").child(usernamee).childByAutoId()

这将在 firebase 中创建一个看起来像这样的新条目:

Bets:
    usernameyoyo:
        -Kfx81GvUxoHpmmMwJ9P:
            Bet: "300",
            ForTeam: "Natus Vincere",
            Username: "usernameyoyo"

---

那么现在的问题是如何获得所下的赌注？嗯，这实际上很简单，因为每个人都是唯一标识的:

func getBetsFor(_ username: String) {
    ref.child("Bets".child(username).observe(.childAdded, with: { snapshot in
        //
        // this is the unique identifier of the bet.  eg, -Kfx81GvUxoHpmmMwJ9P
        let betId = snapshot.key as String

        guard let dict = snapshot.value as? [String: AnyHashable] else {
            print("failed to get dictionary from Bets.\(username)")
            return
        }

        let bet = dict["Bet"] as? String
        let forTeam = dict["ForTeam"] as? String


        // do something with the above information!

    })
}