Swift 3.0 iOS10通过用于Firebase的segue发件人传递异步数据

Question

我有一个登录页面来收集用户名和密码。在提交时，它将发送到数据库以检索我们的服务器访问密钥。我通过使用session.dataTask的异步JSON POST来完成此操作。当我检索JSON对象时，我将它解析出来。我想将它传递到下一页，检索Firebase令牌，然后将这两部分数据发送回服务器进行数据库存储。我创建了一个“准备继续”函数，收集变量并将其传递给下一页的变量。我相信我没有正确设置事件序列，或者数据没有超出Async容器。有人可以看看这两个文件，看看我错了吗？

这里是第一页我想从制作REST Web服务调用后Segue公司了......

loginVC.swift：

import UIKit 

class LoginVC: UIViewController { 

    @IBOutlet weak var username: UITextField! 
    @IBOutlet weak var password: UITextField! 
    @IBOutlet weak var validationBox: UITextView! 
    @IBAction func logInAction(_ sender: UIButton) { 
     guard let user = username.text, !user.isEmpty else { 
      validationBox.text = "Please enter valid credentials" 
      return 
     } 
     guard let pass = password.text, !pass.isEmpty else { 
      validationBox.text = "Please enter valid credentials" 
      return 
     } 

     let params = ["sUser": username.text!, "sPass": password.text!] 

     let url = URL(string: "restWebServiceURL")! 
     let session = URLSession.shared 
     var request = URLRequest(url: url) 
     request.httpMethod = "POST" 
     do { 
      request.httpBody = try JSONSerialization.data(withJSONObject: params, options: .prettyPrinted) 
     } catch let error { 
      print(error.localizedDescription) 
     } 
     request.addValue("application/json", forHTTPHeaderField: "Content-Type") 
     request.addValue("application/json", forHTTPHeaderField: "Accept") 

     let task = session.dataTask(with: request as URLRequest, completionHandler: { data, response, error in 

      guard error == nil else { return } 
      guard let data = data else { return } 

      do { 
       if let parsedJSON = try JSONSerialization.jsonObject(with: data, options: .mutableContainers) as? [String: Any] { 
        let parsedData = parsedJSON["d"] as! [String:Any] 
        let key = parsedData["key"] as! String 
        DispatchQueue.main.async { 
         print(key) 
         self.performSegue(withIdentifier: "FirebaseVC", sender: key) 
        } 

       } 
      } catch let error { 
       print(error.localizedDescription) 
      } 
     }) 
     task.resume() 
    } 
    func sayHello() { 
     print("Hello!") 
    } 
    func sayGoodbye() { 
     print("Goodbye!") 
    } 



    override func viewDidLoad() { 
     super.viewDidLoad() 
     validationBox.text = "Ready..." 
     func prepare(for segue: UIStoryboardSegue, sender: Any?) { 
      if let FirebaseInit = segue.destination as? FirebaseVC { 
       if let sKey = sender as? String { 
        print("prepare - " + sKey) 
        FirebaseInit.sessionKey = sKey 
       } 
      } 
     } 
    } 

    override func didReceiveMemoryWarning() { 
     super.didReceiveMemoryWarning() 
     // Dispose of any resources that can be recreated. 
    } 


} 

这里是我想去的页面接收到的数据访问密钥...

FirebaseVC.swift：

import UIKit 

class FirebaseVC: UIViewController { 

    private var _sessionKey = String() 

    var sessionKey : String { 
     get { return _sessionKey } 
     set { _sessionKey = newValue } 
    } 

    @IBOutlet weak var sessionKeyTestBox: UITextView! 

    override func viewDidLoad() { 
     super.viewDidLoad() 
     print(_sessionKey) 

    } 

    override func didReceiveMemoryWarning() { 
     super.didReceiveMemoryWarning() 
     // Dispose of any resources that can be recreated. 
    } 



} 

随意建议将数据传递到下一页的更好方法。谢谢...

Answer 1

事实证明，在我的假设中，我认为事件链是关闭的。继@achrefGassoumi提出的模型，我搬到了datatask一个集服务在这里：

import Foundation 

struct CallWebService { 

    static let sharedInstance = CallWebService() 

    func logInToCaduceus(u: String, p: String, completion: @escaping (_ sKey: String) ->()) { 
     let params = ["sUser": u, "sPass": p] 

     let url = URL(string: "https://telemed.caduceususa.com/ws/telemed.asmx/telemedLogin")! 
     let session = URLSession.shared 
     var request = URLRequest(url: url) 
     request.httpMethod = "POST" 
     do { 
      request.httpBody = try JSONSerialization.data(withJSONObject: params, options: .prettyPrinted) 
     } catch let error { 
      print(error.localizedDescription) 
     } 
     request.addValue("application/json", forHTTPHeaderField: "Content-Type") 
     request.addValue("application/json", forHTTPHeaderField: "Accept") 

     let task = session.dataTask(with: request as URLRequest, completionHandler: { data, response, error in 

      guard error == nil else { return } 
      guard let data = data else { return } 

      do { 
       if let parsedJSON = try JSONSerialization.jsonObject(with: data, options: .mutableContainers) as? [String: Any] { 
        let parsedData = parsedJSON["d"] as! [String:Any] 
        let key = parsedData["key"] as! String 
        DispatchQueue.main.async { 
         completion(key) 
        } 
       } 
      } catch let error { 
       print(error.localizedDescription) 
      } 
     }) 
     task.resume() 

    } 

} 

然后我的两个控制器是这样的：

LoginVC

import UIKit 

class LoginVC: UIViewController { 

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) { 
     if (segue.destination.isKind(of: FirebaseVC.self)) { 
      let vc = segue.destination as! FirebaseVC 
      if let sKey = sender as? String { 
       vc.sessionKey = sKey 
      } 
     } 
    } 

    @IBOutlet weak var username: UITextField! 
    @IBOutlet weak var password: UITextField! 
    @IBOutlet weak var validationBox: UITextView! 
    @IBAction func logInAction(_ sender: UIButton) { 
     guard let user = username.text, !user.isEmpty else { 
      validationBox.text = "Please enter valid credentials" 
      return 
     } 
     guard let pass = password.text, !pass.isEmpty else { 
      validationBox.text = "Please enter valid credentials" 
      return 
     } 

     CallWebService.sharedInstance.logInToCaduceus(u: username.text!, p: password.text!, completion: {(sessionKey: String) -> Void in 
       print(sessionKey) 
       self.performSegue(withIdentifier: "FirebaseVC", sender: sessionKey) 
      } 
     ) 

    } 

    override func viewDidLoad() { 
     super.viewDidLoad() 
     //validationBox.textAlignment = .center 
     validationBox.text = "Ready..." 
    } 

    override func didReceiveMemoryWarning() { 
     super.didReceiveMemoryWarning() 
     // Dispose of any resources that can be recreated. 
    } 


} 

和接收FirebaseVC

import UIKit 

class FirebaseVC: UIViewController { 

    private var _sessionKey = String() 

    var sessionKey : String { 
     get { return _sessionKey } 
     set { _sessionKey = newValue } 
    } 

    @IBOutlet weak var sessionKeyTestBox: UITextView! 

    override func viewDidLoad() { 
     super.viewDidLoad() 
     sessionKeyTestBox.text = _sessionKey 
    } 

    override func didReceiveMemoryWarning() { 
     super.didReceiveMemoryWarning() 
    } 

} 

对不起我的（非快速）Javascript术语，但es基本上我将数据调用移动到服务中，然后使用完成方法在服务中放置回调方法，以确保performSegue在数据收到并解析出来之前不会触发。因此，当我将表单数据中的日志提交给服务器时，在异步调用完成之前，segue不会触发。