SwiftUI框架详细解析（十七） —— 基于SwiftUI简单App的Dependency Injection应用（二）

版本记录

版本号	时间
V1.0	2021.01.02 星期六

前言

今天翻阅苹果的API文档，发现多了一个框架SwiftUI，这里我们就一起来看一下这个框架。感兴趣的看下面几篇文章。
1. SwiftUI框架详细解析（一） —— 基本概览（一）
2. SwiftUI框架详细解析（二） —— 基于SwiftUI的闪屏页的创建（一）
3. SwiftUI框架详细解析（三） —— 基于SwiftUI的闪屏页的创建（二）
4. SwiftUI框架详细解析（四） —— 使用SwiftUI进行苹果登录（一）
5. SwiftUI框架详细解析（五） —— 使用SwiftUI进行苹果登录（二）
6. SwiftUI框架详细解析（六） —— 基于SwiftUI的导航的实现（一）
7. SwiftUI框架详细解析（七） —— 基于SwiftUI的导航的实现（二）
8. SwiftUI框架详细解析（八） —— 基于SwiftUI的动画的实现（一）
9. SwiftUI框架详细解析（九） —— 基于SwiftUI的动画的实现（二）
10. SwiftUI框架详细解析（十） —— 基于SwiftUI构建各种自定义图表（一）
11. SwiftUI框架详细解析（十一） —— 基于SwiftUI构建各种自定义图表（二）
12. SwiftUI框架详细解析（十二） —— 基于SwiftUI创建Mind-Map UI（一）
13. SwiftUI框架详细解析（十三） —— 基于SwiftUI创建Mind-Map UI（二）
14. SwiftUI框架详细解析（十四） —— 基于Firebase Cloud Firestore的SwiftUI iOS程序的持久性添加（一）
15. SwiftUI框架详细解析（十五） —— 基于Firebase Cloud Firestore的SwiftUI iOS程序的持久性添加（二）
16. SwiftUI框架详细解析（十六） —— 基于SwiftUI简单App的Dependency Injection应用（一）

源码

1. Swift

首先看下工程组织结构

下面就是源码了

1. PreferencesStore.swift

import Combine
import Foundation

protocol PreferencesStoreProtocol: ObservableObject {
  var friendsListPreference: PrivacyLevel { get set }
  var photosPreference: PrivacyLevel { get set }
  var feedPreference: PrivacyLevel { get set }
  var videoCallsPreference: PrivacyLevel { get set }
  var messagePreference: PrivacyLevel { get set }
  func resetPreferences()
}

final class PreferencesStore: PreferencesStoreProtocol {
  @Published var friendsListPreference = value(for: .friends, defaultValue: .friend) {
    didSet {
      set(value: photosPreference, for: .friends)
    }
  }

  @Published var photosPreference = value(for: .photos, defaultValue: .friend) {
    didSet {
      set(value: photosPreference, for: .photos)
    }
  }

  @Published var feedPreference = value(for: .feed, defaultValue: .friend) {
    didSet {
      set(value: feedPreference, for: .feed)
    }
  }

  @Published var videoCallsPreference = value(for: .videoCall, defaultValue: .closeFriend) {
    didSet {
      set(value: videoCallsPreference, for: .videoCall)
    }
  }

  @Published var messagePreference: PrivacyLevel = value(for: .message, defaultValue: .friend) {
    didSet {
      set(value: messagePreference, for: .message)
    }
  }

  func resetPreferences() {
    let defaults = UserDefaults.standard
    PrivacySetting.allCases.forEach { setting in
      defaults.removeObject(forKey: setting.rawValue)
    }
  }

  private static func value(for key: PrivacySetting, defaultValue: PrivacyLevel) -> PrivacyLevel {
    let value = UserDefaults.standard.string(forKey: key.rawValue) ?? ""
    return PrivacyLevel.from(string: value) ?? defaultValue
  }

  private func set(value: PrivacyLevel, for key: PrivacySetting) {
    UserDefaults.standard.setValue(value.title, forKey: key.rawValue)
  }
}

2. PrivacyLevel.swift

import Foundation

enum PrivacyLevel: Comparable {
  case everyone, friend, closeFriend

  var title: String {
    switch self {
    case .everyone:
      return "Everyone"
    case .friend:
      return "Friends only"
    case .closeFriend:
      return "Close friends only"
    }
  }

  static func from(string: String) -> PrivacyLevel? {
    switch string {
    case everyone.title:
      return everyone
    case friend.title:
      return friend
    case closeFriend.title:
      return closeFriend
    default:
      return nil
    }
  }
}

3. UserPreferencesView.swift

import SwiftUI
import Combine

struct UserPreferencesView<Store>: View where Store: PreferencesStoreProtocol {
  private var store: Store

  // swiftlint:disable:next force_unwrapping
  init(store: Store = DIContainer.shared.resolve(type: Store.self)!) {
    self.store = store
  }

  var body: some View {
    NavigationView {
      VStack {
        PreferenceView(title: .photos, value: store.photosPreference) { value in
          store.photosPreference = value
        }
        PreferenceView(title: .friends, value: store.friendsListPreference) { value in
          store.friendsListPreference = value
        }
        PreferenceView(title: .feed, value: store.feedPreference) { value in
          store.feedPreference = value
        }
        PreferenceView(title: .videoCall, value: store.videoCallsPreference) { value in
          store.videoCallsPreference = value
        }
        PreferenceView(title: .message, value: store.messagePreference) { value in
          store.messagePreference = value
        }
        Spacer()
      }
    }.navigationBarTitle("Privacy preferences")
  }
}

struct PreferenceView: View {
  private let title: PrivacySetting
  private let value: PrivacyLevel
  private let onPreferenceUpdated: (PrivacyLevel) -> Void

  init(title: PrivacySetting, value: PrivacyLevel, onPreferenceUpdated: @escaping (PrivacyLevel) -> Void) {
    self.title = title
    self.value = value
    self.onPreferenceUpdated = onPreferenceUpdated
  }

  var body: some View {
    HStack {
      Text(title.rawValue).font(.body)
      Spacer()
      PreferenceMenu(title: value.title, onPreferenceUpdated: onPreferenceUpdated)
    }.padding()
  }
}

struct PreferenceMenu: View {
  @State var title: String
  private let onPreferenceUpdated: (PrivacyLevel) -> Void

  init(title: String, onPreferenceUpdated: @escaping (PrivacyLevel) -> Void) {
    _title = State<String>(initialValue: title)
    self.onPreferenceUpdated = onPreferenceUpdated
  }

  var body: some View {
    Menu(title) {
      Button(PrivacyLevel.closeFriend.title) {
        onPreferenceUpdated(PrivacyLevel.closeFriend)
        title = PrivacyLevel.closeFriend.title
      }
      Button(PrivacyLevel.friend.title) {
        onPreferenceUpdated(PrivacyLevel.friend)
        title = PrivacyLevel.friend.title
      }
      Button(PrivacyLevel.everyone.title) {
        onPreferenceUpdated(PrivacyLevel.everyone)
        title = PrivacyLevel.everyone.title
      }
    }
  }
}

struct UserPreferencesView_Previews: PreviewProvider {
  static var previews: some View {
    UserPreferencesView(store: PreferencesStore())
  }
}

4. ProfileView.swift

import SwiftUI

struct ProfileView<ContentProvider>: View where ContentProvider: ProfileContentProviderProtocol {
  private let user: User
  @ObservedObject private var provider: ContentProvider

  init(
    // swiftlint:disable force_unwrapping
    provider: ContentProvider = DIContainer.shared.resolve(type: ContentProvider.self)!,
    user: User = DIContainer.shared.resolve(type: User.self)!
    // swiftlint:enable force_unwrapping
  ) {
    self.provider = provider
    self.user = user
  }

  var body: some View {
    NavigationView {
      ScrollView(.vertical, showsIndicators: true) {
        VStack {
          ProfileHeaderView(
            user: user,
            canSendMessage: provider.canSendMessage,
            canStartVideoChat: provider.canStartVideoChat
          )
          provider.friendsView
          provider.photosView
          provider.feedView
        }
      }
      .navigationTitle("Profile")
      .navigationBarItems(trailing: Button(action: {}) {
        NavigationLink(destination: UserPreferencesView<PreferencesStore>()) {
          Image(systemName: "gear")
        }
      })
    }
  }
}

struct ProfileView_Previews: PreviewProvider {
  static var previews: some View {
    typealias Provider = ProfileContentProvider<PreferencesStore>
    let container = DIContainer.shared
    container.register(type: PrivacyLevel.self, component: PrivacyLevel.friend)
    container.register(type: User.self, component: Mock.user())
    container.register(type: PreferencesStore.self, component: PreferencesStore())
    container.register(type: Provider.self, component: Provider())
    return ProfileView<Provider>()
  }
}

// MARK: - Profile views

struct PhotosView: View {
  private let photos: [String]

  init(photos: [String]) {
    self.photos = photos
  }

  var body: some View {
    VStack {
      Text("Recent photos").font(.title2)
      ScrollView(.horizontal, showsIndicators: false) {
        HStack {
          ForEach(photos, id: \.self) { url in
            ImageView(withURL: url).frame(width: 200, height: 200).clipped()
          }
        }
      }
    }
  }
}

struct UsersView: View {
  private let users: [User]
  private let title: String

  init(title: String, users: [User]) {
    self.users = users
    self.title = title
  }

  var body: some View {
    VStack {
      Text(title).font(.title2)
      ScrollView(.horizontal, showsIndicators: false) {
        HStack {
          ForEach(users, id: \.self) { user in
            VStack {
              ImageView(withURL: user.imageURL).frame(width: 80, height: 80).clipped()
              Text(user.name)
            }
          }
        }
      }
    }
  }
}

struct ProfileHeaderView: View {
  private let user: User
  private let canSendMessage: Bool
  private let canStartVideoChat: Bool

  init(user: User, canSendMessage: Bool, canStartVideoChat: Bool) {
    self.user = user
    self.canSendMessage = canSendMessage
    self.canStartVideoChat = canStartVideoChat
  }

  var body: some View {
    VStack {
      HStack(alignment: .center, spacing: 16) {
        Spacer()
        if canStartVideoChat {
          Button(action: {}) {
            Image(systemName: "video")
          }
        }
        if canSendMessage {
          Button(action: {}) {
            Image(systemName: "message")
          }
        }
      }.padding(.trailing)
      ImageView(withURL: user.imageURL).clipShape(Circle()).frame(width: 100, height: 100).clipped()
      Text(user.name).font(.largeTitle)
      HStack {
        Image(systemName: "location")
        Text(user.area).font(.subheadline)
      }.padding(2)
      Text(user.bio).font(.body).padding()
    }
  }
}

// MARK: - History feed views

struct HistoryFeedView: View {
  private let posts: [Post]

  init(posts: [Post]) {
    self.posts = posts
  }

  var body: some View {
    ScrollView(.vertical, showsIndicators: true) {
      VStack {
        Text("Recent posts").font(.title2)
        ForEach(posts, id: \.self) { post in
          PostView(post: post)
        }
      }
    }
  }
}

struct PostView: View {
  private let post: Post

  init(post: Post) {
    self.post = post
  }

  var body: some View {
    VStack {
      ImageView(withURL: post.pictureURL).frame(height: 200).clipped()
      HStack {
        Text(post.message)
        Spacer()
        HStack {
          Image(systemName: "hand.thumbsup")
          Text(String(post.likesCount))
        }
        HStack {
          Image(systemName: "bubble.right")
          Text(String(post.commentsCount))
        }
      }.padding()
    }
  }
}

struct RestrictedAccessView: View {
  var body: some View {
    VStack {
      Image(systemName: "eye.slash").padding()
      Text("The access to the full profile info is restricted")
    }
  }
}

5. ImageView.swift

import SwiftUI

struct ImageView: View {
  @ObservedObject var imageLoader: ImageLoader
  @State var image = UIImage(named: "img_placeholder", in: Bundle(for: ImageLoader.self), with: nil) ?? UIImage()

  init(withURL url: String) {
    self.imageLoader = ImageLoader(urlString: url)
  }

  var body: some View {
    Image(uiImage: image)
      .resizable()
      .aspectRatio(contentMode: .fill)
      .onReceive(imageLoader.didChange) { image in
        self.image = image
      }
  }
}

struct ImageView_Previews: PreviewProvider {
  static var previews: some View {
    Image(uiImage: UIImage(named: "img_placeholder") ?? UIImage())
      .resizable()
      .aspectRatio(contentMode: .fill)
      .frame(width: 100, height: 100)
      .clipped()
  }
}

6. SceneDelegate.swift

import UIKit
import SwiftUI

class SceneDelegate: UIResponder, UIWindowSceneDelegate {
  var window: UIWindow?

  typealias Provider = ProfileContentProvider<PreferencesStore>

  func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
    let container = DIContainer.shared
    container.register(type: PrivacyLevel.self, component: PrivacyLevel.friend)
    container.register(type: User.self, component: Mock.user())
    container.register(type: PreferencesStore.self, component: PreferencesStore())
    container.register(type: Provider.self, component: Provider())
    let profileView = ProfileView<Provider>()
    if let windowScene = scene as? UIWindowScene {
      let window = UIWindow(windowScene: windowScene)
      window.rootViewController = UIHostingController(rootView: profileView)
      self.window = window
      window.makeKeyAndVisible()
    }
  }
}

7. AppDelegate.swift

import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate { }

8. User.swift

import Foundation

struct User: Hashable, Equatable {
  let name: String
  let imageURL: String
  let bio: String
  let area: String
  let friends: [User]
  let photos: [String]
  let historyFeed: [Post]

  static func == (lhs: User, rhs: User) -> Bool {
    lhs.name == rhs.name && lhs.imageURL == rhs.imageURL
  }
}

struct Post: Hashable {
  let pictureURL: String
  let message: String
  let likesCount: Int
  let commentsCount: Int
}

9. Mock.swift

import Foundation

enum Mock {
  static func user() -> User {
    return User(
      name: "Belle",
      imageURL: "https://images.unsplash.com/photo-1522593596038-8a7b75a0f2bc?ixlib=rb-1.2.1&auto=format&fit=crop&w=2250&q=80",
      bio: "I love hiking, exploring new countries and traditional dishes",
      area: "Italy",
      friends: friends(),
      photos: photos(),
      historyFeed: posts()
    )
  }

  static func photos() -> [String] {
    return [
      "https://images.unsplash.com/photo-1553808354-74b53671c8b4?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=300&q=80",
      "https://images.unsplash.com/photo-1570996915537-dd53ef642ef7?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=300&q=80",
      "https://images.unsplash.com/photo-1553808353-54724c294f0c?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=300&q=80",
      "https://images.unsplash.com/photo-1552396422-9d90144ceb97?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=300&q=80",
      "https://images.unsplash.com/photo-1573314481772-97f0b6102c17?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=300&q=80",
      "https://images.unsplash.com/photo-1586866928487-2af5b3850105?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=300&q=80"
    ]
  }

  static func posts() -> [Post] {
    return [
      Post(pictureURL: "https://images.unsplash.com/photo-1440186347098-386b7459ad6b?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=300&q=80", message: "", likesCount: 20, commentsCount: 10),
      Post(pictureURL: "https://images.unsplash.com/photo-1501554728187-ce583db33af7?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=300&q=80", message: "Such a nice view!", likesCount: 32, commentsCount: 5),
      Post(pictureURL: "https://images.unsplash.com/photo-1500049242364-5f500807cdd7?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=300&q=80", message: "", likesCount: 20, commentsCount: 10),
      Post(pictureURL: "https://images.unsplash.com/photo-1442570468985-f63ed5de9086?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=300&q=80", message: "", likesCount: 20, commentsCount: 10),
      Post(pictureURL: "https://images.unsplash.com/photo-1574325298943-eacd397f382d?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=300&q=80", message: "I love train rides", likesCount: 20, commentsCount: 10),
      Post(pictureURL: "https://images.unsplash.com/photo-1549872178-96db16a53ca8?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=300&q=80", message: "Ready for a new adventure", likesCount: 20, commentsCount: 10)
    ]
  }

  static func friends() -> [User] {
    return [
      User(name: "Leila", imageURL: "https://images.unsplash.com/photo-1474073705359-5da2a8270c64?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=300&q=80", bio: "", area: "", friends: [], photos: [], historyFeed: []),
      User(name: "Ingrid", imageURL: "https://images.unsplash.com/photo-1520512202623-51c5c53957df?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=300&q=80", bio: "", area: "", friends: [], photos: [], historyFeed: []),
      User(name: "Leon", imageURL: "https://images.unsplash.com/photo-1534614971-6be99a7a3ffd?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=300&q=80", bio: "", area: "", friends: [], photos: [], historyFeed: []),
      User(name: "Jonathan", imageURL: "https://images.unsplash.com/photo-1484517186945-df8151a1a871?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=300&q=80", bio: "", area: "", friends: [], photos: [], historyFeed: []),
      User(name: "Jay", imageURL: "https://images.unsplash.com/photo-1485361767769-5ceffc9f2144?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=300&q=80", bio: "", area: "", friends: [], photos: [], historyFeed: []),
      User(name: "Harriette", imageURL: "https://images.unsplash.com/photo-1468817814611-b7edf94b5d60?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=300&q=80", bio: "", area: "", friends: [], photos: [], historyFeed: [])
    ]
  }
}

10. ImageLoader.swift

import Combine
import SwiftUI

class ImageLoader: ObservableObject {
  var didChange = PassthroughSubject<UIImage, Never>()
  var image = UIImage() {
    didSet {
      didChange.send(image)
    }
  }

  init(urlString: String) {
    guard let url = URL(string: urlString) else { return }
    let task = URLSession.shared.dataTask(with: url) { data, _, _ in
      guard let data = data else { return }
      DispatchQueue.main.async {
        self.image = UIImage(data: data) ?? UIImage()
      }
    }
    task.resume()
  }
}

11. PrivacySetting.swift

enum PrivacySetting: String, CaseIterable {
  case photos = "Who can see my photos",
  friends = "Who can see my friends list",
  feed = "Who can see my feed",
  videoCall = "Who can video call me",
  message = "Who can message me"
}

12. ProfileContentProvider.swift

import SwiftUI
import Combine

protocol ProfileContentProviderProtocol: ObservableObject {
  var privacyLevel: PrivacyLevel { get }
  var canSendMessage: Bool { get }
  var canStartVideoChat: Bool { get }
  var photosView: AnyView { get }
  var feedView: AnyView { get }
  var friendsView: AnyView { get }
}

final class ProfileContentProvider<Store>: ProfileContentProviderProtocol where Store: PreferencesStoreProtocol {
  let privacyLevel: PrivacyLevel
  private let user: User
  private var store: Store
  private var cancellables: Set<AnyCancellable> = []

  init(
    // swiftlint:disable force_unwrapping
    privacyLevel: PrivacyLevel = DIContainer.shared.resolve(type: PrivacyLevel.self)!,
    user: User = DIContainer.shared.resolve(type: User.self)!,
    store: Store = DIContainer.shared.resolve(type: Store.self)!
    // swiftlint:enable force_unwrapping
  ) {
    self.privacyLevel = privacyLevel
    self.user = user
    self.store = store

    store.objectWillChange.sink { _ in
      self.objectWillChange.send()
    }
    .store(in: &cancellables)
  }

  var canSendMessage: Bool {
    privacyLevel >= store.messagePreference
  }

  var canStartVideoChat: Bool {
    privacyLevel >= store.videoCallsPreference
  }

  var photosView: AnyView {
    privacyLevel >= store.photosPreference ? AnyView(PhotosView(photos: user.photos)) : AnyView(EmptyView())
  }

  var feedView: AnyView {
    privacyLevel >= store.feedPreference ? AnyView(HistoryFeedView(posts: user.historyFeed)) : AnyView(EmptyView())
  }

  var friendsView: AnyView {
    privacyLevel >= store.friendsListPreference ?
      AnyView(UsersView(title: "Friends", users: user.friends)) :
      AnyView(EmptyView())
  }
}

13. DIContainer.swift

import Foundation

protocol DIContainerProtocol {
  func register<Component>(type: Component.Type, component: Any)
  func resolve<Component>(type: Component.Type) -> Component?
}

final class DIContainer: DIContainerProtocol {
  static let shared = DIContainer()

  private init() {}

  var components: [String: Any] = [:]

  func register<Component>(type: Component.Type, component: Any) {
    components["\(type)"] = component
  }

  func resolve<Component>(type: Component.Type) -> Component? {
    return components["\(type)"] as? Component
  }
}

后记

本篇主要讲述了基于SwiftUI简单App的Dependency Injection应用，感兴趣的给个赞或者关注~~~

人面猴
序言：七十年代末，一起剥皮案震惊了整个滨河市，随后出现的几起案子，更是在滨河造成了极大的恐慌，老刑警刘岩，带你破解...
沈念sama阅读 214,444评论 6赞 496
死咒
序言：滨河连续发生了三起死亡事件，死亡现场离奇诡异，居然都是意外死亡，警方通过查阅死者的电脑和手机，发现死者居然都...
沈念sama阅读 91,421评论 3赞 389
救了他两次的神仙让他今天三更去死
文/潘晓璐我一进店门，熙熙楼的掌柜王于贵愁眉苦脸地迎上来，“玉大人，你说我怎么就摊上这事。” “怎么了？”我有些...
开封第一讲书人阅读 160,036评论 0赞 349
道士缉凶录：失踪的卖姜人
文/不坏的土叔我叫张陵，是天一观的道长。经常有香客问我，道长，这世上最难降的妖魔是什么？我笑而不...
开封第一讲书人阅读 57,363评论 1赞 288
港岛之恋（遗憾婚礼）
正文为了忘掉前任，我火速办了婚礼，结果婚礼上，老公的妹妹穿的比我还像新娘。我一直安慰自己，他们只是感情好，可当我...
茶点故事阅读 66,460评论 6赞 386
恶毒庶女顶嫁案：这布局不是一般人想出来的
文/花漫我一把揭开白布。她就那样静静地躺着，像睡着了一般。火红的嫁衣衬着肌肤如雪。梳的纹丝不乱的头发上，一...
开封第一讲书人阅读 50,502评论 1赞 292
城市分裂传说
那天，我揣着相机与录音，去河边找鬼。笑死，一个胖子当着我的面吹牛，可吹牛的内容都是我干的。我是一名探鬼主播，决...
沈念sama阅读 39,511评论 3赞 412
双鸳鸯连环套：你想象不到人心有多黑
文/苍兰香墨我猛地睁开眼，长吁一口气：“原来是场噩梦啊……” “哼！你这毒妇竟也来了？” 一声冷哼从身侧响起，我...
开封第一讲书人阅读 38,280评论 0赞 270
万荣杀人案实录
序言：老挝万荣一对情侣失踪，失踪者是张志新（化名）和其女友刘颖，没想到半个月后，有当地人在树林里发现了一具尸体，经...
沈念sama阅读 44,736评论 1赞 307
护林员之死
正文独居荒郊野岭守林人离奇死亡，尸身上长有42处带血的脓包…… 初始之章·张勋以下内容为张勋视角年9月15日...
茶点故事阅读 37,014评论 2赞 328
白月光启示录
正文我和宋清朗相恋三年，在试婚纱的时候发现自己被绿了。大学时的朋友给我发了我未婚夫和他白月光在一起吃饭的照片。...
茶点故事阅读 39,190评论 1赞 342
活死人
序言：一个原本活蹦乱跳的男人离奇死亡，死状恐怖，灵堂内的尸体忽然破棺而出，到底是诈尸还是另有隐情，我是刑警宁泽，带...
沈念sama阅读 34,848评论 5赞 338
日本核电站爆炸内幕
正文年R本政府宣布，位于F岛的核电站，受9级特大地震影响，放射性物质发生泄漏。R本人自食恶果不足惜，却给世界环境...
茶点故事阅读 40,531评论 3赞 322
男人毒药：我在死后第九天来索命
文/蒙蒙一、第九天我趴在偏房一处隐蔽的房顶上张望。院中可真热闹，春花似锦、人声如沸。这庄子的主人今日做“春日...
开封第一讲书人阅读 31,159评论 0赞 21
一桩弑父案，背后竟有这般阴谋
文/苍兰香墨我抬头看了看天上的太阳。三九已至，却和暖如春，着一层夹袄步出监牢的瞬间，已是汗流浃背。一阵脚步声响...
开封第一讲书人阅读 32,411评论 1赞 268
情欲美人皮
我被黑心中介骗来泰国打工，没想到刚下飞机就差点儿被人妖公主榨干…… 1. 我叫王不留，地道东北人。一个月前我还...
沈念sama阅读 47,067评论 2赞 365
代替公主和亲
正文我出身青楼，却偏偏与公主长得像，于是被迫代替她去往敌国和亲。传闻我的和亲对象是个残疾皇子，可洞房花烛夜当晚...
茶点故事阅读 44,078评论 2赞 352

SwiftUI框架详细解析 （十七） —— 基于SwiftUI简单App的Dependency Injection应用（二）

版本记录

前言

源码

1. Swift

后记

推荐阅读更多精彩内容

SwiftUI框架详细解析（十七） —— 基于SwiftUI简单App的Dependency Injection应用（二）