ios-swift-development

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English

🇨🇳

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iOS Swift Development

iOS Swift 开发

Overview

概述

Build high-performance native iOS applications using Swift with modern frameworks including SwiftUI, Combine, and async/await patterns.

使用Swift结合SwiftUI、Combine和async/await等现代框架构建高性能原生iOS应用。

When to Use

适用场景

Creating native iOS applications with optimal performance
Leveraging iOS-specific features and APIs
Building apps that require tight hardware integration
Using SwiftUI for declarative UI development
Implementing complex animations and transitions

开发具备最优性能的原生iOS应用
利用iOS专属功能与API
开发需要紧密硬件集成的应用
使用SwiftUI进行声明式UI开发
实现复杂动画与过渡效果

Instructions

操作步骤

1. MVVM Architecture Setup

1. MVVM架构搭建

swift

import Foundation
import Combine

struct User: Codable, Identifiable {
  let id: UUID
  var name: String
  var email: String
}

class UserViewModel: ObservableObject {
  @Published var user: User?
  @Published var isLoading = false
  @Published var errorMessage: String?

  private let networkService: NetworkService

  init(networkService: NetworkService = .shared) {
    self.networkService = networkService
  }

  @MainActor
  func fetchUser(id: UUID) async {
    isLoading = true
    errorMessage = nil

    do {
      user = try await networkService.fetch(User.self, from: "/users/\(id)")
    } catch {
      errorMessage = error.localizedDescription
    }

    isLoading = false
  }

  @MainActor
  func updateUser(_ userData: User) async {
    guard let user = user else { return }

    do {
      self.user = try await networkService.put(
        User.self,
        to: "/users/\(user.id)",
        body: userData
      )
    } catch {
      errorMessage = "Failed to update user"
    }
  }

  func logout() {
    user = nil
    errorMessage = nil
  }
}

swift

import Foundation
import Combine

struct User: Codable, Identifiable {
  let id: UUID
  var name: String
  var email: String
}

class UserViewModel: ObservableObject {
  @Published var user: User?
  @Published var isLoading = false
  @Published var errorMessage: String?

  private let networkService: NetworkService

  init(networkService: NetworkService = .shared) {
    self.networkService = networkService
  }

  @MainActor
  func fetchUser(id: UUID) async {
    isLoading = true
    errorMessage = nil

    do {
      user = try await networkService.fetch(User.self, from: "/users/\(id)")
    } catch {
      errorMessage = error.localizedDescription
    }

    isLoading = false
  }

  @MainActor
  func updateUser(_ userData: User) async {
    guard let user = user else { return }

    do {
      self.user = try await networkService.put(
        User.self,
        to: "/users/\(user.id)",
        body: userData
      )
    } catch {
      errorMessage = "Failed to update user"
    }
  }

  func logout() {
    user = nil
    errorMessage = nil
  }
}

2. Network Service with URLSession

2. 基于URLSession的网络服务

swift

class NetworkService {
  static let shared = NetworkService()

  private let session: URLSession
  private let baseURL: URL

  init(
    session: URLSession = .shared,
    baseURL: URL = URL(string: "https://api.example.com")!
  ) {
    self.session = session
    self.baseURL = baseURL
  }

  func fetch<T: Decodable>(
    _: T.Type,
    from endpoint: String
  ) async throws -> T {
    let url = baseURL.appendingPathComponent(endpoint)
    var request = URLRequest(url: url)
    request.addAuthHeader()

    let (data, response) = try await session.data(for: request)
    try validateResponse(response)

    let decoder = JSONDecoder()
    decoder.dateDecodingStrategy = .iso8601
    return try decoder.decode(T.self, from: data)
  }

  func put<T: Decodable, Body: Encodable>(
    _: T.Type,
    to endpoint: String,
    body: Body
  ) async throws -> T {
    let url = baseURL.appendingPathComponent(endpoint)
    var request = URLRequest(url: url)
    request.httpMethod = "PUT"
    request.addAuthHeader()
    request.setValue("application/json", forHTTPHeaderField: "Content-Type")

    let encoder = JSONEncoder()
    encoder.dateEncodingStrategy = .iso8601
    request.httpBody = try encoder.encode(body)

    let (data, response) = try await session.data(for: request)
    try validateResponse(response)

    let decoder = JSONDecoder()
    return try decoder.decode(T.self, from: data)
  }

  private func validateResponse(_ response: URLResponse) throws {
    guard let httpResponse = response as? HTTPURLResponse else {
      throw NetworkError.invalidResponse
    }

    switch httpResponse.statusCode {
    case 200...299:
      return
    case 401:
      throw NetworkError.unauthorized
    case 500...599:
      throw NetworkError.serverError
    default:
      throw NetworkError.unknown
    }
  }
}

enum NetworkError: LocalizedError {
  case invalidResponse
  case unauthorized
  case serverError
  case unknown

  var errorDescription: String? {
    switch self {
    case .invalidResponse: return "Invalid response"
    case .unauthorized: return "Unauthorized"
    case .serverError: return "Server error"
    case .unknown: return "Unknown error"
    }
  }
}

extension URLRequest {
  mutating func addAuthHeader() {
    if let token = KeychainManager.shared.getToken() {
      setValue("Bearer \(token)", forHTTPHeaderField: "Authorization")
    }
  }
}

swift

class NetworkService {
  static let shared = NetworkService()

  private let session: URLSession
  private let baseURL: URL

  init(
    session: URLSession = .shared,
    baseURL: URL = URL(string: "https://api.example.com")!
  ) {
    self.session = session
    self.baseURL = baseURL
  }

  func fetch<T: Decodable>(
    _: T.Type,
    from endpoint: String
  ) async throws -> T {
    let url = baseURL.appendingPathComponent(endpoint)
    var request = URLRequest(url: url)
    request.addAuthHeader()

    let (data, response) = try await session.data(for: request)
    try validateResponse(response)

    let decoder = JSONDecoder()
    decoder.dateDecodingStrategy = .iso8601
    return try decoder.decode(T.self, from: data)
  }

  func put<T: Decodable, Body: Encodable>(
    _: T.Type,
    to endpoint: String,
    body: Body
  ) async throws -> T {
    let url = baseURL.appendingPathComponent(endpoint)
    var request = URLRequest(url: url)
    request.httpMethod = "PUT"
    request.addAuthHeader()
    request.setValue("application/json", forHTTPHeaderField: "Content-Type")

    let encoder = JSONEncoder()
    encoder.dateEncodingStrategy = .iso8601
    request.httpBody = try encoder.encode(body)

    let (data, response) = try await session.data(for: request)
    try validateResponse(response)

    let decoder = JSONDecoder()
    return try decoder.decode(T.self, from: data)
  }

  private func validateResponse(_ response: URLResponse) throws {
    guard let httpResponse = response as? HTTPURLResponse else {
      throw NetworkError.invalidResponse
    }

    switch httpResponse.statusCode {
    case 200...299:
      return
    case 401:
      throw NetworkError.unauthorized
    case 500...599:
      throw NetworkError.serverError
    default:
      throw NetworkError.unknown
    }
  }
}

enum NetworkError: LocalizedError {
  case invalidResponse
  case unauthorized
  case serverError
  case unknown

  var errorDescription: String? {
    switch self {
    case .invalidResponse: return "Invalid response"
    case .unauthorized: return "Unauthorized"
    case .serverError: return "Server error"
    case .unknown: return "Unknown error"
    }
  }
}

extension URLRequest {
  mutating func addAuthHeader() {
    if let token = KeychainManager.shared.getToken() {
      setValue("Bearer \(token)", forHTTPHeaderField: "Authorization")
    }
  }
}

3. SwiftUI Views

3. SwiftUI 视图

swift

struct ContentView: View {
  @StateObject var userViewModel = UserViewModel()

  var body: some View {
    TabView {
      HomeView()
        .tabItem { Label("Home", systemImage: "house") }

      ProfileView(viewModel: userViewModel)
        .tabItem { Label("Profile", systemImage: "person") }
    }
  }
}

struct HomeView: View {
  @State var items: [Item] = []
  @State var loading = true

  var body: some View {
    NavigationView {
      ZStack {
        if loading {
          ProgressView()
        } else {
          List(items) { item in
            NavigationLink(destination: ItemDetailView(item: item)) {
              VStack(alignment: .leading) {
                Text(item.title).font(.headline)
                Text(item.description).font(.subheadline).foregroundColor(.gray)
              }
            }
          }
        }
      }
      .navigationTitle("Items")
      .task {
        await loadItems()
      }
    }
  }

  private func loadItems() async {
    do {
      items = try await NetworkService.shared.fetch([Item].self, from: "/items")
    } catch {
      print("Error: \(error)")
    }
    loading = false
  }
}

struct ItemDetailView: View {
  let item: Item
  @Environment(\.dismiss) var dismiss

  var body: some View {
    ScrollView {
      VStack(alignment: .leading, spacing: 16) {
        Text(item.title).font(.title2).fontWeight(.bold)
        Text(item.description).font(.body)
        Text("Price: $\(String(format: "%.2f", item.price))")
          .font(.headline).foregroundColor(.blue)
        Spacer()
      }
      .padding()
    }
    .navigationBarTitleDisplayMode(.inline)
  }
}

struct ProfileView: View {
  @ObservedObject var viewModel: UserViewModel
  @State var isLoading = true

  var body: some View {
    NavigationView {
      ZStack {
        if viewModel.isLoading {
          ProgressView()
        } else if let user = viewModel.user {
          VStack(spacing: 20) {
            Text(user.name).font(.title).fontWeight(.bold)
            Text(user.email).font(.subheadline)
            Button("Logout") { viewModel.logout() }
              .foregroundColor(.red)
            Spacer()
          }
          .padding()
        } else {
          Text("No profile data")
        }
      }
      .navigationTitle("Profile")
      .task {
        await viewModel.fetchUser(id: UUID())
      }
    }
  }
}

struct Item: Codable, Identifiable {
  let id: String
  let title: String
  let description: String
  let price: Double
}

swift

struct ContentView: View {
  @StateObject var userViewModel = UserViewModel()

  var body: some View {
    TabView {
      HomeView()
        .tabItem { Label("Home", systemImage: "house") }

      ProfileView(viewModel: userViewModel)
        .tabItem { Label("Profile", systemImage: "person") }
    }
  }
}

struct HomeView: View {
  @State var items: [Item] = []
  @State var loading = true

  var body: some View {
    NavigationView {
      ZStack {
        if loading {
          ProgressView()
        } else {
          List(items) { item in
            NavigationLink(destination: ItemDetailView(item: item)) {
              VStack(alignment: .leading) {
                Text(item.title).font(.headline)
                Text(item.description).font(.subheadline).foregroundColor(.gray)
              }
            }
          }
        }
      }
      .navigationTitle("Items")
      .task {
        await loadItems()
      }
    }
  }

  private func loadItems() async {
    do {
      items = try await NetworkService.shared.fetch([Item].self, from: "/items")
    } catch {
      print("Error: \(error)")
    }
    loading = false
  }
}

struct ItemDetailView: View {
  let item: Item
  @Environment(\.dismiss) var dismiss

  var body: some View {
    ScrollView {
      VStack(alignment: .leading, spacing: 16) {
        Text(item.title).font(.title2).fontWeight(.bold)
        Text(item.description).font(.body)
        Text("Price: $\(String(format: "%.2f", item.price))")
          .font(.headline).foregroundColor(.blue)
        Spacer()
      }
      .padding()
    }
    .navigationBarTitleDisplayMode(.inline)
  }
}

struct ProfileView: View {
  @ObservedObject var viewModel: UserViewModel
  @State var isLoading = true

  var body: some View {
    NavigationView {
      ZStack {
        if viewModel.isLoading {
          ProgressView()
        } else if let user = viewModel.user {
          VStack(spacing: 20) {
            Text(user.name).font(.title).fontWeight(.bold)
            Text(user.email).font(.subheadline)
            Button("Logout") { viewModel.logout() }
              .foregroundColor(.red)
            Spacer()
          }
          .padding()
        } else {
          Text("No profile data")
        }
      }
      .navigationTitle("Profile")
      .task {
        await viewModel.fetchUser(id: UUID())
      }
    }
  }
}

struct Item: Codable, Identifiable {
  let id: String
  let title: String
  let description: String
  let price: Double
}

Best Practices

最佳实践

✅ DO

✅ 建议

Use SwiftUI for modern UI development
Implement MVVM architecture
Use async/await patterns
Store sensitive data in Keychain
Handle errors gracefully
Use @StateObject for ViewModels
Validate API responses properly
Implement Core Data for persistence
Test on multiple iOS versions
Use dependency injection
Follow Swift style guidelines

使用SwiftUI进行现代UI开发
实现MVVM架构
使用async/await模式
将敏感数据存储在Keychain中
优雅处理错误
为ViewModels使用@StateObject
正确验证API响应
实现Core Data进行数据持久化
在多个iOS版本上测试
使用依赖注入
遵循Swift编码风格指南

❌ DON'T

❌ 避免

Store tokens in UserDefaults
Make network calls on main thread
Use deprecated UIKit patterns
Ignore memory leaks
Skip error handling
Use force unwrapping (!)
Store passwords in code
Ignore accessibility
Deploy untested code
Use hardcoded API URLs

在UserDefaults中存储令牌
在主线程中发起网络请求
使用已弃用的UIKit模式
忽略内存泄漏
跳过错误处理
使用强制解包(!)
在代码中存储密码
忽略无障碍访问
部署未测试的代码
使用硬编码的API地址