如何将网络代码与视图控制器分开

我在用 Alamofire 以便在此时提出邮寄请求。我第一次建造它是在 ViewController 然后工作。但是我想把它分开 class . 我用 singleton 当我打电话给 可视控制器 . 唯一的问题是,在状态恢复成功后,我试图实例化另一个状态 可视控制器 当用户登录时。我不想在网络课上做,我想在我的视图控制器里做。我怎样才能做到这一点?

enum Status: Int {
    case Success = 200
    case Failure = 401
}

enum HTTPMethod: String {
    case Post = "POST"
    case Get = "GET" 
}

enum APIKey: String {
    case value = "somevalueeeeeeeee"
    case key = "somekeyyyyyyyyyyyyyy"
}

import Foundation
import Alamofire
import UIKit

class NetworkManager {
    static let shared = NetworkManager()

    func makePostRequest(url: URL, params: Parameters, headers: HTTPHeaders, credential: URLCredential) {
        Alamofire.request(url, method: .post, parameters: params, headers: headers).authenticate(usingCredential: credential)
            .responseJSON { response in
                print(response)
                let status = response.response?.statusCode
                switch status {
                case Status.Success.rawValue:
                    print("I would like to instantiate my viewcontroller here")
                case Status.Failure.rawValue:
                    print("Bad Request")
                default:
                    break
                }
        }
    }
}

import UIKit
import Alamofire

class LoginViewController: UIViewController {
    @IBOutlet weak var emailTextField: UITextField!
    @IBOutlet weak var passwordTextfield: UITextField!

    private func login() {
        guard let userName = emailTextField.text else { return }
        guard let passWord = passwordTextfield.text else { return }

        let params: Parameters = [
            "username": userName,
            "password": passWord
        ]
        guard let url = URL(string: URLS.url.rawValue) else { return }
        let headers = [APIKey.key.rawValue: APIKey.value.rawValue]
        let credential = URLCredential(user: userName, password: passWord, persistence: .forSession)

        NetworkManager.shared.makePostRequest(url: url, params: params, headers: headers, credential: credential)
    }

    @IBAction func onLoginTapped(_ sender: UIButton) {
            login()
        }
    }