如何在 Swift 中将数据从一个模型传递到另一个模型？

我正在处理一个包含“创建新帐户”视图控制器及其随附的名为“CreateNewAccount”的 Swift 类的项目。用户可以在这个视图控制器中放置 4 个输入值，名字、姓氏、用户名和密码。单击此 VC 中的“创建帐户”按钮后，4 个输入值将传递给一个名为 UserInfoRetrieveModel 的 Swift 类（我相信在 MVC 的模型层内），它们应该存储在那里。

然后我想将这些值传递给另一个名为 UserInfoModel 的 Swift 类（也是一个模型），然后它将第一个名称值委托给位于名为“ThanksForJoining”的 VC 中的 label 的文本值（及其随附的班级）。

我已经弄清楚如何将值从 VC 传递到模型（CreateNewAccount 到 UserInfoRetrieveModel）以及从模型到 VC（UserInfoModel 到ThanksForJoining），但是在我从模型到模型（UserInfoRetrieveModel 到 UserInfoModel）的转移中，最初输入到“CreateNewAccount， " 我想传递给第二个模型类 UserInfoModel 变为 nil。

下面是 CreateNewAccount、UserInfoRetrieve、UserInfo 和ThanksForJoining 的代码：

创建新帐户 ->

import UIKit

class CreateNewAccount: UIViewController{

@IBOutlet weak var FNInput: UITextField!
@IBOutlet weak var LNInput: UITextField!
@IBOutlet weak var usernameInput: UITextField!
@IBOutlet weak var passwordInput: UITextField!

var uInfoRetrieve = UInfoRetrieveModel()

@IBAction func thanksForJoining(_ sender: Any) {
    uInfoRetrieve.firstName = FNInput.text!
    uInfoRetrieve.lastName = LNInput.text!
    uInfoRetrieve.userName = usernameInput.text!
    uInfoRetrieve.password = passwordInput.text!
    uInfoRetrieve.delegate = self
    uInfoRetrieve.retrieving()
}
override func viewDidLoad() {
    super.viewDidLoad()
}

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

extension CreateNewAccount: UInfoRetrieveModelDelegate{
    func credentialTransfer(data: String) {
      print(data)
  }
}

用户信息检索 ->

import Foundation

protocol UInfoRetrieveModelDelegate: class {
  func credentialTransfer(data:String)
 }


class UInfoRetrieveModel: NSObject {

   weak var delegate: UInfoRetrieveModelDelegate?

     var firstName: String = ""
     var lastName: String = ""
     var userName: String = ""
     var password: String = ""

func retrieving(){


    delegate?.credentialTransfer(data: firstName)
    delegate?.credentialTransfer(data: lastName)
    delegate?.credentialTransfer(data: userName)
    delegate?.credentialTransfer(data: password)
    }

}

用户信息 ->

import Foundation

protocol UserInfoModelDelegate: class {
    func didReceiveDataUpdate(data: String)
   }

class UserInfoModel {
   weak var delegate: UserInfoModelDelegate?

   let uInfoRetrieve = UInfoRetrieveModel()

   func requestData() -> Array<String> {

    let firstName = uInfoRetrieve.firstName
    let lastName = uInfoRetrieve.lastName
    let userName = uInfoRetrieve.userName
    let password = uInfoRetrieve.password

    delegate?.didReceiveDataUpdate(data: firstName)
    delegate?.didReceiveDataUpdate(data: lastName)
    delegate?.didReceiveDataUpdate(data: userName)
    delegate?.didReceiveDataUpdate(data: password)
    let credentials = [firstName, lastName, userName, password] as [Any]
    return credentials as! Array<String>
  }
}  

感谢加入 ->

import UIKit

class ThanksForJoining: UIViewController {

   var userInfo = UserInfoModel()


  @IBOutlet weak var firstName: UILabel!

  override func viewDidLoad() {
    super.viewDidLoad()
    userInfo.delegate = self
    firstName.text = userInfo.requestData()[0]
    print("yo")
    print(userInfo.requestData()[0])
}

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

extension ThanksForJoining: UserInfoModelDelegate {

   func didReceiveDataUpdate(data: String) {
      print(data)
   }
}