这是MVVM基础用法,
相比MVP, 最大的不同点在于, MVVM要负责对V的更新
Model
// Person.swift
struct Person {
let firstName: String
let lastName: String
}
ViewModel
// GreetinViewModel.swift
protocol GreetingViewModelProtocol {
var greeting: String? {get}
var greetingDidChange:((GreetingViewModelProtocol)->())? { get set }
init(person: Person)
func showGreeting()
}
class GreetingViewModel : GreetingViewModelProtocol {
let person: Person
required init(person: Person) {
self.person = person
}
var greeting: String? {
didSet {
// VM的值被更新后, 再去更新V
self.greetingDidChange!(self)
}
}
var greetingDidChange: ((GreetingViewModelProtocol) -> ())?
func showGreeting() {
self.greeting = "Hello \(person.firstName) \(person.lastName)"
}
}
View
// ViewController.swift
import UIKit
class ViewController: UIViewController {
@IBOutlet weak var lbTitle: UILabel!
var person:Person? = nil
var viewModel:GreetingViewModelProtocol! {
didSet {
// 负责VM更新V
self.viewModel.greetingDidChange = { vm in
self.lbTitle.text = vm.greeting
}
}
}
@IBAction func onClick(_ sender: Any) {
// V更新VM
self.viewModel.showGreeting()
}
override func viewDidLoad() {
super.viewDidLoad()
person = Person(firstName: "Gao", lastName: "L")
self.viewModel = GreetingViewModel(person: person!)
}
}
