如何在iOS项目中正确实现Stripe？

Question

Im developing an iOS app and its includes selling goods outside of the app so I downloaded Stripe using Cocoapods and placing it in my poodle. I know I have correctly installed in my app and input my test API key, because it import Stripe line works just fine. However I am having trouble creating a token. Every time I try to run my code in the simulator and try to make a purchase it prints there was an error. I don't know if its because I implemented the wrong line of code somewhere or left some out, so I was wondering if anybody could help me figure out why the purchase isn't going through? I know I don't have a backend set up but I'm not trying to send the token to the server yet I'm just trying to make sure my app is connected to Stripe which is the first step of 6 that require to actually make a purchase. Thanks for your help in advance.

Code for view controller before the one that lets user (through firebase authentication) make a purchase and stores data:

import UIKit

class PaymentInfoController: UIViewController {


@IBOutlet weak var paymentLabel: UILabel!
@IBOutlet weak var cardField: UITextField!
@IBOutlet weak var cvcField: UITextField!
@IBOutlet weak var expField: UITextField! 

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {   

    if let checkoutVC = segue.destination as? CheckoutController {
        checkoutVC.cardNumber = self.cardField.text!
        checkoutVC.cvc = self.cvcField.text!

        if self.expField.text?.isEmpty == false {

            expField.text?.contains("0123456789/")
            (expField.text?.characters.count)! <= 7
        let expDate = self.expField.text?.components(separatedBy: "/")
        let expMonth = UInt((expDate?[0])!)
        let expYear = UInt((expDate?[1])!)

        checkoutVC.expMon = expMonth!
        checkoutVC.expYear = expYear!
        }
    }
}

@IBAction func checkout(_ sender: Any) {
    performSegue(withIdentifier: "checkout", sender: self)  
}

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view.
}

Code for view controller where the purchase is made:

import UIKit
import FirebaseAuth
import FirebaseDatabase
import Firebase
import Stripe

    class CheckoutController: UIViewController {

    let ref = Database.database().reference()

    @IBOutlet weak var feeLabel: UILabel!
    @IBOutlet weak var amountLabel: UILabel!

    var cardNumber = String()
    var cvc = String()
    var expMon = UInt()
    var expYear = UInt()

    @IBAction func purchase(_ sender: Any) {

        if Auth.auth().currentUser != nil {

            // Initiate the card
            let stripCard = STPCard()

            STPAPIClient.shared().createToken(withCard: stripCard, completion: { (token, error) -> Void in

                if error != nil {

                    print("There is an error")
                } 

                else {

                    // Send the card info to Strip to get the token
                    stripCard.number = self.cardNumber
                    stripCard.cvc = self.cvc
                    stripCard.expMonth = UInt(self.expMon)
                    stripCard.expYear = UInt(self.expYear)

                    let alert = UIAlertController(title: "Your Stripe token is " + (token?.tokenId)!, message: "", preferredStyle: .alert)
                    let defaultAction = UIAlertAction(title: "OK", style: .default, handler: nil)
                    alert.addAction(defaultAction)
                    self.present(alert, animated: true, completion: nil)
                    print(token!)
                }
            })

        }
    }

    override func viewDidLoad() {
        super.viewDidLoad()

    let user = Auth.auth().currentUser
        let userID: String = (user?.uid)!

        if user != nil {

      let totalRef = ref.child("users/\(userID)").child("Total")
          totalRef.observeSingleEvent(of: .value, with: { (snapshot) in
            let cost = snapshot.value as! Int
            self.totalLabel.text = "\(cost) bookies"

            let total = (Double(cost) * 1.35) + 1.39

            self.amountLabel.text = "$\(total)"
        }) 
    }
}

Answer 1

The problem is that you're submitting a blank STPCard. You are calling the createToken method without setting any of the fields on the card. For some reason, it looks like you're only setting the card fields in the Completion block after you've gotten a token. You need to move these lines:

 stripCard.number = self.cardNumber
 stripCard.cvc = self.cvc
 stripCard.expMonth = UInt(self.expMon)
 stripCard.expYear = UInt(self.expYear)

up before you make the call to createToken.