如何在iOS上使用MVVM进行路由详解

func loginButtonTapped() {
 // Start network request...
 // Upon response:
 if viewModel.shouldChangePassword {
 performSegue(id: "ChangePasswordScreen", sender: nil)
 } else {
 performSegue(id: "HomeScreen", sender: nil)
 }
}

protocol Router {
 func route(
 to routeID: String, 
 from context: UIViewController, 
 parameters: Any?
 )
}

class LoginViewController: UIViewController {
 
 enum Route: String {
  case login
  case signUp
  case forgotPassword
 }
 
 var viewModel: LoginViewModel!
 var router: Router!
 
 ...
 
 func loginButtonTapped() {
  router.route(to: Route.login.rawValue, from: self)
 }
 
 func signUpTapped() {
  router.route(to: Route.signUp.rawValue, from: self)
 }
 
 func forgotPasswordTapped() {
  router.route(to: Route.forgotPassword.rawValue, from: self)
 }
}

class LoginRouter: Router {
 
 unowned var viewModel: LoginViewModel
 
 init(viewModel: LoginViewModel) {
  self.viewModel = viewModel
 }
 
 func route(
  to routeID: String, 
  from context: UIViewController, 
  parameters: Any?) 
 {
  guard let route = LoginVC.Route(rawValue: routeID) else {
   return
  }
  switch route {
  case .login:
   if viewModel.shouldChangePassword {
   // Push change-password-screen.
   } else {
   // Push home-screen.
   }
  case .signUp:
   // Push sign-up-screen:
   let vc = SignUpViewController()
   let vm = SignUpViewModel()
   vc.viewModel = vm
   vc.router = SignUpRouter(viewModel: vm)
   context.navigationController.push(vc, animated: true)
  case . forgotPasswordScreen:
   // Push forgot-password-screen.
  }
 }
}