引言：为什么需要一个优秀的登录界面
在移动应用开发中，登录界面是用户与应用交互的第一道门槛。一个设计精良、功能完善的登录界面不仅能提升用户体验，还能保障用户数据的安全。本教程将带你从零开始，使用Swift和UIKit构建一个既美观又安全的iOS登录界面，并深入探讨输入验证、网络请求处理等实际开发中的关键问题。
1. 项目准备与界面搭建
1.1 创建新项目
首先，打开Xcode，创建一个新的iOS项目：
选择”App”模板
语言设置为Swift
界面选择Storyboard（为了更直观地展示UI构建过程）
1.2 设计登录界面
在Storyboard中，我们拖拽以下UI组件构建登录表单：
// 在LoginViewController.swift中声明UI组件
class LoginViewController: UIViewController {
// 主容器视图
private let containerView: UIView = {
let view = UIView()
view.backgroundColor = .systemBackground
view.layer.cornerRadius = 12
view.layer.shadowColor = UIColor.label.cgColor
view.layer.shadowOpacity = 0.1
view.layer.shadowOffset = CGSize(width: 0, height: 2)
view.layer.shadowRadius = 4
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
// 标题标签
private let titleLabel: UILabel = {
let label = UILabel()
label.text = "欢迎回来"
label.font = UIFont.systemFont(ofSize: 24, weight: .bold)
label.textAlignment = .center
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
// 用户名输入框
private let usernameTextField: UITextField = {
let textField = UITextField()
textField.placeholder = "用户名/邮箱"
textField.borderStyle = .roundedRect
textField.autocapitalizationType = .none
textField.autocorrectionType = .no
textField.translatesAutoresizingMaskIntoConstraints = false
return textField
}()
// 密码输入框
private let passwordTextField: UITextField = {
let textField = UITextField()
textField.placeholder = "密码"
textField.borderStyle = .roundedRect
textField.isSecureTextEntry = true
textField.translatesAutoresizingMaskIntoConstraints = false
return textField
}()
// 登录按钮
private let loginButton: UIButton = {
let button = UIButton(type: .system)
button.setTitle("登录", for: .normal)
button.backgroundColor = .systemBlue
button.setTitleColor(.white, for: .normal)
button.layer.cornerRadius = 8
button.titleLabel?.font = UIFont.systemFont(ofSize: 16, weight: .bold)
button.translatesAutoresizingMaskIntoConstraints = false
return button
}()
// 忘记密码按钮
private let forgotPasswordButton: UIButton = {
let button = UIButton(type: .system)
button.setTitle("忘记密码?", for: .normal)
button.setTitleColor(.systemGray, for: .normal)
button.titleLabel?.font = UIFont.systemFont(ofSize: 14)
button.translatesAutoresizingMaskIntoConstraints = false
return button
}()
// 注册按钮
private let registerButton: UIButton = {
let button = UIButton(type: .system)
let attributedTitle = NSAttributedString(
string: "没有账号? 立即注册",
attributes: [
.font: UIFont.systemFont(ofSize: 14),
.foregroundColor: UIColor.systemGray
]
)
button.setAttributedTitle(attributedTitle, for: .normal)
button.translatesAutoresizingMaskIntoConstraints = false
return button
}()
// 活动指示器
private let activityIndicator: UIActivityIndicatorView = {
let indicator = UIActivityIndicatorView(style: .medium)
indicator.color = .white
indicator.hidesWhenStopped = true
indicator.translatesAutoresizingMaskIntoConstraints = false
return indicator
}()
// 错误提示标签
private let errorLabel: UILabel = {
let label = UILabel()
label.textColor = .systemRed
label.font = UIFont.systemFont(ofSize: 12)
label.textAlignment = .center
label.numberOfLines = 0
label.isHidden = true
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
// 视图控制器生命周期
override func viewDidLoad() {
super.viewDidLoad()
setupUI()
setupConstraints()
setupActions()
setupTapGesture()
}
// 设置UI
private func setupUI() {
view.backgroundColor = .systemGroupedBackground
// 添加子视图
view.addSubview(containerView)
containerView.addSubview(titleLabel)
containerView.addSubview(usernameTextField)
containerView.addSubview(passwordTextField)
containerView.addSubview(loginButton)
containerView.addSubview(forgotPasswordButton)
containerView.addSubview(activityIndicator)
containerView.addSubview(errorLabel)
view.addSubview(registerButton)
}
// 设置约束
private func setupConstraints() {
NSLayoutConstraint.activate([
// 容器视图约束
containerView.centerXAnchor.constraint(equalTo: view.centerXAnchor),
containerView.centerYAnchor.constraint(equalTo: view.centerYAnchor, constant: -50),
containerView.widthAnchor.constraint(equalToConstant: 300),
containerView.heightAnchor.constraint(equalToConstant: 350),
// 标题标签约束
titleLabel.topAnchor.constraint(equalTo: containerView.topAnchor, constant: 20),
titleLabel.leadingAnchor.constraint(equalTo: containerView.leadingAnchor, constant: 20),
titleLabel.trailingAnchor.constraint(equalTo: containerView.trailingAnchor, constant: -20),
titleLabel.heightAnchor.constraint(equalToConstant: 30),
// 用户名输入框约束
usernameTextField.topAnchor.constraint(equalTo: titleLabel.bottomAnchor, constant: 20),
usernameTextField.leadingAnchor.constraint(equalTo: containerView.leadingAnchor, constant: 20),
usernameTextField.trailingAnchor.constraint(equalTo: containerView.trailingAnchor, constant: -20),
usernameTextField.heightAnchor.constraint(equalToConstant: 40),
// 密码输入框约束
passwordTextField.topAnchor.constraint(equalTo: usernameTextField.bottomAnchor, constant: 15),
passwordTextField.leadingAnchor.constraint(equalTo: containerView.leadingAnchor, constant: 20),
passwordTextField.trailingAnchor.constraint(equalTo: containerView.trailingAnchor, constant: -20),
passwordTextField.heightAnchor.constraint(equalToConstant: 40),
// 登录按钮约束
loginButton.topAnchor.constraint(equalTo: passwordTextField.bottomAnchor, constant: 20),
loginButton.leadingAnchor.constraint(equalTo: containerView.leadingAnchor, constant: 20),
loginButton.trailingAnchor.constraint(equalTo: containerView.trailingAnchor, constant: -20),
loginButton.heightAnchor.constraint(equalToConstant: 44),
// 忘记密码按钮约束
forgotPasswordButton.topAnchor.constraint(equalTo: loginButton.bottomAnchor, constant: 10),
forgotPasswordButton.centerXAnchor.constraint(equalTo: containerView.centerXAnchor),
forgotPasswordButton.heightAnchor.constraint(equalToConstant: 20),
// 活动指示器约束
activityIndicator.centerXAnchor.constraint(equalTo: loginButton.centerXAnchor),
activityIndicator.centerYAnchor.constraint(equalTo: loginButton.centerYAnchor),
// 错误标签约束
errorLabel.topAnchor.constraint(equalTo: forgotPasswordButton.bottomAnchor, constant: 10),
errorLabel.leadingAnchor.constraint(equalTo: containerView.leadingAnchor, constant: 20),
errorLabel.trailingAnchor.constraint(equalTo: containerView.trailingAnchor, constant: -20),
errorLabel.heightAnchor.constraint(greaterThanOrEqualToConstant: 20),
// 注册按钮约束
registerButton.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor, constant: -20),
registerButton.centerXAnchor.constraint(equalTo: view.centerXAnchor),
registerButton.heightAnchor.constraint(equalToConstant: 20)
])
}
// 设置按钮动作
private func setupActions() {
loginButton.addTarget(self, action: #selector(loginButtonTapped), for: .touchUpInside)
forgotPasswordButton.addTarget(self, action: #selector(forgotPasswordTapped), for: .touchUpInside)
registerButton.addTarget(self, action: #selector(registerTapped), for: .touchUpInside)
}
// 设置点击手势（收起键盘）
private func setupTapGesture() {
let tap = UITapGestureRecognizer(target: self, action: #selector(dismissKeyboard))
view.addGestureRecognizer(tap)
}
// MARK: - Action Methods
@objc private func loginButtonTapped() {
// 后续实现
}
@objc private func forgotPasswordTapped() {
// 后续实现
}
@objc private func registerTapped() {
// 后续实现
}
@objc private func dismissKeyboard() {
view.endEditing(true)
}
}
1.3 界面优化与美化
为了提升用户体验，我们可以添加一些视觉优化：
// 在LoginViewController中添加以下方法
private func setupUIAppearance() {
// 设置渐变背景
let gradientLayer = CAGradientLayer()
gradientLayer.frame = view.bounds
gradientLayer.colors = [
UIColor.systemBlue.cgColor,
UIColor.systemPurple.cgColor
]
gradientLayer.startPoint = CGPoint(x: 0, y: 0)
gradientLayer.endPoint = CGPoint(x: 1, y: 1)
view.layer.insertSublayer(gradientLayer, at: 0)
// 设置输入框样式
[usernameTextField, passwordTextField].forEach { textField in
textField?.backgroundColor = .systemBackground.withAlphaComponent(0.9)
textField?.layer.cornerRadius = 8
textField?.layer.borderWidth = 1
textField?.layer.borderColor = UIColor.systemGray5.cgColor
textField?.leftView = UIView(frame: CGRect(x: 0, y: 0, width: 10, height: 0))
textField?.leftViewMode = .always
}
// 设置登录按钮样式
loginButton.layer.shadowColor = UIColor.systemBlue.cgColor
loginButton.layer.shadowOpacity = 0.3
loginButton.layer.shadowOffset = CGSize(width: 0, height: 2)
loginButton.layer.shadowRadius = 4
}
// 在viewDidLoad中调用
override func viewDidLoad() {
super.viewDidLoad()
setupUIAppearance() // 添加这行
setupUI()
setupConstraints()
setupActions()
setupTapGesture()
}
2. 输入验证逻辑实现
2.1 验证规则设计
在实际应用中，我们需要对用户输入进行严格验证：
// 创建一个验证工具类
struct InputValidator {
// 验证用户名
static func validateUsername(_ username: String) -> ValidationResult {
// 去除首尾空格
let trimmedUsername = username.trimmingCharacters(in: .whitespacesAndNewlines)
// 检查是否为空
if trimmedUsername.isEmpty {
return .failure("用户名不能为空")
}
// 检查长度
if trimmedUsername.count < 3 {
return .failure("用户名至少需要3个字符")
}
if trimmedUsername.count > 30 {
return .failure("用户名不能超过30个字符")
}
// 检查格式（允许字母、数字、下划线、连字符）
let allowedCharacters = CharacterSet(charactersIn: "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-")
if trimmedUsername.rangeOfCharacter(from: allowedCharacters.inverted) != nil {
return .failure("用户名只能包含字母、数字、下划线和连字符")
}
return .success(trimmedUsername)
}
// 验证邮箱
static func validateEmail(_ email: String) -> ValidationResult {
let trimmedEmail = email.trimmingCharacters(in: .whitespacesAndNewlines)
if trimmedEmail.isEmpty {
return .failure("邮箱不能为空")
}
// 简单的邮箱格式验证
let emailRegex = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,64}"
let emailPredicate = NSPredicate(format: "SELF MATCHES %@", emailRegex)
if !emailPredicate.evaluate(with: trimmedEmail) {
return .failure("请输入有效的邮箱地址")
}
return .success(trimmedEmail)
}
// 验证密码
static func validatePassword(_ password: String) -> ValidationResult {
let trimmedPassword = password.trimmingCharacters(in: .whitespacesAndNewlines)
if trimmedPassword.isEmpty {
return .failure("密码不能为空")
}
if trimmedPassword.count < 8 {
return .failure("密码至少需要8个字符")
}
if trimmedPassword.count > 64 {
return .failure("密码不能超过64个字符")
}
// 检查密码强度（至少包含字母和数字）
let letterRegex = ".*[A-Za-z]+.*"
let numberRegex = ".*[0-9]+.*"
let letterPredicate = NSPredicate(format: "SELF MATCHES %@", letterRegex)
let numberPredicate = NSPredicate(format: "SELF MATCHES %@", numberRegex)
if !letterPredicate.evaluate(with: trimmedPassword) || !numberPredicate.evaluate(with: trimmedPassword) {
return .failure("密码必须包含字母和数字")
}
return .success(trimmedPassword)
}
// 验证结果枚举
enum ValidationResult {
case success(String)
case failure(String)
var isValid: Bool {
switch self {
case .success:
return true
case .failure:
return false
}
}
var value: String? {
switch self {
case .success(let value):
return value
case .failure:
return nil
}
}
var errorMessage: String? {
switch self {
case .success:
return nil
case .failure(let message):
return message
}
}
}
}
2.2 集成验证到登录流程
在登录按钮点击事件中集成验证：
@objc private func loginButtonTapped() {
// 收起键盘
dismissKeyboard()
// 隐藏之前的错误信息
errorLabel.isHidden = true
// 获取输入值
guard let username = usernameTextField.text,
let password = passwordTextField.text else {
showError("输入框不能为空")
return
}
// 验证用户名（可以是用户名或邮箱）
let usernameValidation: InputValidator.ValidationResult
if username.contains("@") {
usernameValidation = InputValidator.validateEmail(username)
} else {
usernameValidation = InputValidator.validateUsername(username)
}
guard usernameValidation.isValid else {
showError(usernameValidation.errorMessage ?? "用户名格式错误")
return
}
// 验证密码
let passwordValidation = InputValidator.validatePassword(password)
guard passwordValidation.isValid else {
showError(passwordValidation.errorMessage ?? "密码格式错误")
return
}
// 验证通过，开始登录流程
performLogin(with: usernameValidation.value!, password: passwordValidation.value!)
}
private func showError(_ message: String) {
errorLabel.text = message
errorLabel.isHidden = false
// 添加动画效果
UIView.animate(withDuration: 0.3, delay: 0, usingSpringWithDamping: 0.7, initialSpringVelocity: 0.5, options: []) {
self.view.layoutIfNeeded()
}
}
3. 网络请求与安全处理
3.1 网络请求封装
使用URLSession封装一个安全的网络请求管理器：
import Foundation
// 网络错误枚举
enum NetworkError: Error, LocalizedError {
case invalidURL
case noData
case decodingError
case serverError(statusCode: Int)
case unauthorized
case networkUnavailable
case timeout
var errorDescription: String? {
switch self {
case .invalidURL:
return "无效的URL"
case .noData:
return "服务器未返回数据"
case .decodingError:
return "数据解析失败"
case .serverError(let statusCode):
return "服务器错误 (状态码: \(statusCode))"
case .unauthorized:
return "认证失败，请重新登录"
case .networkUnavailable:
return "网络不可用"
case .timeout:
return "请求超时"
}
}
}
// 网络请求管理器
class NetworkManager {
static let shared = NetworkManager()
private let session: URLSession
private let timeoutInterval: TimeInterval = 30
private init() {
let configuration = URLSessionConfiguration.default
configuration.timeoutIntervalForRequest = timeoutInterval
configuration.timeoutIntervalForResource = timeoutInterval
configuration.waitsForConnectivity = true
configuration.requestCachePolicy = .reloadIgnoringLocalCacheData
self.session = URLSession(configuration: configuration)
}
// 通用请求方法
func request
endpoint: String,
method: String = "GET",
parameters: [String: Any]? = nil,
headers: [String: String]? = nil,
responseType: T.Type
) async throws -> T {
// 检查网络状态
guard await NetworkReachability.shared.isConnected else {
throw NetworkError.networkUnavailable
}
// 构建URL
guard let url = URL(string: endpoint) else {
throw NetworkError.invalidURL
}
// 构建请求
var request = URLRequest(url: url)
request.httpMethod = method
request.timeoutInterval = timeoutInterval
// 设置请求头
if let headers = headers {
for (key, value) in headers {
request.setValue(value, forHTTPHeaderField: key)
}
}
// 设置请求体
if let parameters = parameters, method != "GET" {
request.httpBody = try? JSONSerialization.data(withJSONObject: parameters)
request.setValue("application/json", forHTTPHeaderField: "Content-Type")
}
// 发送请求
let (data, response) = try await session.data(for: request)
// 检查响应状态
guard let httpResponse = response as? HTTPURLResponse else {
throw NetworkError.serverError(statusCode: 0)
}
switch httpResponse.statusCode {
case 200...299:
// 成功响应，解析数据
do {
let decodedResponse = try JSONDecoder().decode(T.self, from: data)
return decodedResponse
} catch {
throw NetworkError.decodingError
}
case 401:
throw NetworkError.unauthorized
case 400...499:
throw NetworkError.serverError(statusCode: httpResponse.statusCode)
case 500...599:
throw NetworkError.serverError(statusCode: httpResponse.statusCode)
default:
throw NetworkError.serverError(statusCode: httpResponse.statusCode)
}
}
// 专门的登录请求方法
func login(username: String, password: String) async throws -> LoginResponse {
let parameters: [String: Any] = [
"username": username,
"password": password,
"device_info": getDeviceInfo()
]
let headers = [
"User-Agent": "MyApp/1.0 (iOS)",
"Accept": "application/json"
]
return try await request(
endpoint: "https://api.example.com/auth/login",
method: "POST",
parameters: parameters,
headers: headers,
responseType: LoginResponse.self
)
}
// 获取设备信息
private func getDeviceInfo() -> [String: String] {
return [
"platform": "iOS",
"device_model": UIDevice.current.model,
"system_version": UIDevice.current.systemVersion,
"app_version": Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String ?? "1.0"
]
}
}
// 响应模型
struct LoginResponse: Codable {
let success: Bool
let token: String?
let user: User?
let message: String?
}
struct User: Codable {
let id: String
let username: String
let email: String
let createdAt: String
enum CodingKeys: String, CodingKey {
case id, username, email
case createdAt = "created_at"
}
}
// 网络状态检查
class NetworkReachability {
static let shared = NetworkReachability()
private let monitor = NWPathMonitor()
private let queue = DispatchQueue(label: "NetworkReachability")
private init() {
monitor.pathUpdateHandler = { path in
self.isConnected = (path.status == .satisfied)
}
monitor.start(queue: queue)
}
private(set) var isConnected: Bool = true
}
3.2 在登录流程中集成网络请求
更新登录按钮点击事件：
@objc private func loginButtonTapped() {
// ... 前面的验证逻辑 ...
// 验证通过，开始登录流程
performLogin(with: usernameValidation.value!, password: passwordValidation.value!)
}
private func performLogin(with username: String, password: String) {
// 显示加载状态
setLoadingState(true)
// 使用async/await进行异步请求
Task {
do {
let loginResponse = try await NetworkManager.shared.login(username: username, password: password)
// 在主线程更新UI
await MainActor.run {
handleLoginResponse(response: loginResponse)
}
} catch let error as NetworkError {
await MainActor.run {
handleNetworkError(error)
}
} catch {
await MainActor.run {
showError("未知错误: \(error.localizedDescription)")
}
}
}
}
private func handleLoginResponse(response: LoginResponse) {
setLoadingState(false)
if response.success, let token = response.token {
// 登录成功，保存token
TokenManager.shared.saveToken(token)
// 跳转到主界面
navigateToMainScreen()
} else {
showError(response.message ?? "登录失败")
}
}
private func handleNetworkError(_ error: NetworkError) {
setLoadingState(false)
showError(error.localizedDescription)
}
private func setLoadingState(_ isLoading: Bool) {
if isLoading {
loginButton.setTitle("", for: .normal)
activityIndicator.startAnimating()
loginButton.isEnabled = false
} else {
activityIndicator.stopAnimating()
loginButton.setTitle("登录", for: .normal)
loginButton.isEnabled = true
}
}
private func navigateToMainScreen() {
// 创建主界面
let mainVC = MainViewController()
mainVC.modalPresentationStyle = .fullScreen
// 添加过渡动画
if let window = view.window {
UIView.transition(with: window, duration: 0.5, options: .transitionCrossDissolve) {
window.rootViewController = mainVC
}
}
}
3.3 Token安全管理
创建Token管理器来安全存储认证信息：
import Security
class TokenManager {
static let shared = TokenManager()
private let tokenKey = "auth_token"
private let keychainService = "com.yourapp.auth"
private init() {}
// 保存token到Keychain
func saveToken(_ token: String) {
// 先删除旧的
deleteToken()
let data = token.data(using: .utf8)!
let query: [String: Any] = [
kSecClass as String: kSecClassGenericPassword,
kSecAttrService as String: keychainService,
kSecAttrAccount as String: tokenKey,
kSecValueData as String: data,
kSecAttrAccessible as String: kSecAttrAccessibleWhenUnlocked
]
SecItemAdd(query as CFDictionary, nil)
}
// 从Keychain读取token
func getToken() -> String? {
let query: [String: Any] = [
kSecClass as String: kSecClassGenericPassword,
kSecAttrService as String: keychainService,
kSecAttrAccount as String: tokenKey,
kSecReturnData as String: true,
kSecMatchLimit as String: kSecMatchLimitOne
]
var result: AnyObject?
let status = SecItemCopyMatching(query as CFDictionary, &result)
guard status == errSecSuccess,
let data = result as? Data,
let token = String(data: data, encoding: .utf8) else {
return nil
}
return token
}
// 删除token
func deleteToken() {
let query: [String: Any] = [
kSecClass as String: kSecClassGenericPassword,
kSecAttrService as String: keychainService,
kSecAttrAccount as String: tokenKey
]
SecItemDelete(query as CFDictionary)
}
// 检查是否已登录
func isLoggedIn() -> Bool {
return getToken() != nil
}
}
4. 常见问题解决方案
4.1 处理键盘遮挡问题
当键盘弹出时，可能会遮挡输入框：
// 在LoginViewController中添加键盘通知处理
override func viewDidLoad() {
super.viewDidLoad()
// ... 其他设置 ...
setupKeyboardNotifications()
}
private func setupKeyboardNotifications() {
NotificationCenter.default.addObserver(
self,
selector: #selector(keyboardWillShow),
name: UIResponder.keyboardWillShowNotification,
object: nil
)
NotificationCenter.default.addObserver(
self,
selector: #selector(keyboardWillHide),
name: UIResponder.keyboardWillHideNotification,
object: nil
)
}
@objc private func keyboardWillShow(notification: NSNotification) {
guard let userInfo = notification.userInfo,
let keyboardFrame = userInfo[UIResponder.keyboardFrameEndUserInfoKey] as? CGRect,
let duration = userInfo[UIResponder.keyboardAnimationDurationUserInfoKey] as? Double else {
return
}
let keyboardHeight = keyboardFrame.height
// 调整容器视图的Y位置
if containerView.frame.origin.y == 0 {
UIView.animate(withDuration: duration) {
self.containerView.transform = CGAffineTransform(translationX: 0, y: -keyboardHeight / 2)
}
}
}
@objc private func keyboardWillHide(notification: NSNotification) {
guard let userInfo = notification.userInfo,
let duration = userInfo[UIResponder.keyboardAnimationDurationUserInfoKey] as? Double else {
return
}
UIView.animate(withDuration: duration) {
self.containerView.transform = .identity
}
}
deinit {
NotificationCenter.default.removeObserver(self)
}
4.2 处理网络超时和重试
实现自动重试机制：
// 扩展NetworkManager添加重试功能
extension NetworkManager {
func requestWithRetry
endpoint: String,
method: String = "GET",
parameters: [String: Any]? = nil,
headers: [String: String]? = nil,
responseType: T.Type,
maxRetries: Int = 3,
retryDelay: TimeInterval = 2.0
) async throws -> T {
var lastError: Error?
for attempt in 0...maxRetries {
do {
return try await request(
endpoint: endpoint,
method: method,
parameters: parameters,
headers: headers,
responseType: responseType
)
} catch {
lastError = error
// 如果是最后一次尝试，或者某些错误不应该重试
if attempt == maxRetries || shouldNotRetry(error: error) {
throw error
}
// 等待后重试
try await Task.sleep(nanoseconds: UInt64(retryDelay * 1_000_000_000))
}
}
throw lastError ?? NetworkError.networkUnavailable
}
private func shouldNotRetry(error: Error) -> Bool {
guard let networkError = error as? NetworkError else {
return false
}
// 这些错误不应该重试
switch networkError {
case .unauthorized, .invalidURL:
return true
default:
return false
}
}
}
// 在登录中使用带重试的请求
private func performLoginWithRetry(username: String, password: String) {
setLoadingState(true)
Task {
do {
let loginResponse = try await NetworkManager.shared.requestWithRetry(
endpoint: "https://api.example.com/auth/login",
method: "POST",
parameters: [
"username": username,
"password": password
],
headers: ["Accept": "application/json"],
responseType: LoginResponse.self,
maxRetries: 2
)
await MainActor.run {
handleLoginResponse(response: loginResponse)
}
} catch {
await MainActor.run {
handleNetworkError(error)
}
}
}
}
4.3 实现离线缓存策略
使用UserDefaults缓存最后的登录状态：
class OfflineCacheManager {
static let shared = OfflineCacheManager()
private let defaults = UserDefaults.standard
private let lastLoginKey = "last_login_info"
private init() {}
// 保存登录信息
func saveLastLogin(username: String, timestamp: Date = Date()) {
let info: [String: Any] = [
"username": username,
"timestamp": timestamp.timeIntervalSince1970
]
defaults.set(info, forKey: lastLoginKey)
}
// 获取最后登录信息
func getLastLogin() -> (username: String, timestamp: Date)? {
guard let info = defaults.dictionary(forKey: lastLoginKey),
let username = info["username"] as? String,
let timestamp = info["timestamp"] as? TimeInterval else {
return nil
}
// 检查是否过期（7天）
let date = Date(timeIntervalSince1970: timestamp)
if Date().timeIntervalSince(date) > 7 * 24 * 60 * 60 {
return nil
}
return (username, date)
}
// 清除缓存
func clearLastLogin() {
defaults.removeObject(forKey: lastLoginKey)
}
}
// 在登录成功后保存
private func handleLoginResponse(response: LoginResponse) {
if response.success, let token = response.token, let username = response.user?.username {
TokenManager.shared.saveToken(token)
OfflineCacheManager.shared.saveLastLogin(username: username)
navigateToMainScreen()
}
}
// 在登录界面加载时填充用户名
override func viewDidLoad() {
super.viewDidLoad()
// ... 其他设置 ...
// 如果有缓存的登录信息，填充用户名
if let lastLogin = OfflineCacheManager.shared.getLastLogin() {
usernameTextField.text = lastLogin.username
}
}
4.4 实现生物识别登录
集成Face ID/Touch ID：
import LocalAuthentication
class BiometricAuthManager {
static let shared = BiometricAuthManager()
private let context = LAContext()
private init() {}
// 检查设备是否支持生物识别
func isBiometricAvailable() -> Bool {
var error: NSError?
let isAvailable = context.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: &error)
return isAvailable
}
// 获取生物识别类型
func getBiometricType() -> String {
var error: NSError?
context.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: &error)
if let error = error as? LAError {
if error.code == .biometryNotAvailable {
return "不可用"
}
}
if context.biometryType == .faceID {
return "Face ID"
} else if context.biometryType == .touchID {
return "Touch ID"
} else {
return "无"
}
}
// 执行生物识别验证
func authenticate(completion: @escaping (Bool, Error?) -> Void) {
let reason = "使用生物识别登录您的账户"
context.evaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, localizedReason: reason) { success, error in
DispatchQueue.main.async {
completion(success, error)
}
}
}
}
// 在登录界面添加生物识别按钮
private let biometricLoginButton: UIButton = {
let button = UIButton(type: .system)
button.setTitle("使用Face ID登录", for: .normal)
button.backgroundColor = .systemGray6
button.setTitleColor(.label, for: .normal)
button.layer.cornerRadius = 8
button.translatesAutoresizingMaskIntoConstraints = false
button.isHidden = true // 默认隐藏
return button
}()
// 在viewDidLoad中配置
private func setupBiometricButton() {
if BiometricAuthManager.shared.isBiometricAvailable() {
biometricLoginButton.isHidden = false
biometricLoginButton.setTitle(
"使用\(BiometricAuthManager.shared.getBiometricType())登录",
for: .normal
)
biometricLoginButton.addTarget(self, action: #selector(biometricLoginTapped), for: .touchUpInside)
}
}
@objc private func biometricLoginTapped() {
BiometricAuthManager.shared.authenticate { [weak self] success, error in
if success {
// 从Keychain获取token并自动登录
if let token = TokenManager.shared.getToken() {
self?.navigateToMainScreen()
} else {
self?.showError("请先进行一次密码登录")
}
} else {
self?.showError(error?.localizedDescription ?? "生物识别验证失败")
}
}
}
5. 完整的登录流程整合
5.1 完整的LoginViewController
将所有功能整合到一个完整的视图控制器中：
import UIKit
import LocalAuthentication
import Network
class LoginViewController: UIViewController {
// MARK: - UI Components
private let backgroundImage: UIImageView = {
let imageView = UIImageView(image: UIImage(systemName: "waveform.path.ecg"))
imageView.contentMode = .scaleAspectFill
imageView.alpha = 0.1
imageView.translatesAutoresizingMaskIntoConstraints = false
return imageView
}()
private let containerView: UIView = {
let view = UIView()
view.backgroundColor = .systemBackground
view.layer.cornerRadius = 16
view.layer.shadowColor = UIColor.label.cgColor
view.layer.shadowOpacity = 0.1
view.layer.shadowOffset = CGSize(width: 0, height: 4)
view.layer.shadowRadius = 8
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
private let titleLabel: UILabel = {
let label = UILabel()
label.text = "欢迎回来"
label.font = UIFont.systemFont(ofSize: 28, weight: .bold)
label.textAlignment = .center
label.textColor = .label
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
private let subtitleLabel: UILabel = {
let label = UILabel()
label.text = "请登录您的账户"
label.font = UIFont.systemFont(ofSize: 14, weight: .regular)
label.textAlignment = .center
label.textColor = .secondaryLabel
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
private let usernameTextField: UITextField = {
let textField = UITextField()
textField.placeholder = "用户名或邮箱"
textField.borderStyle = .roundedRect
textField.autocapitalizationType = .none
textField.autocorrectionType = .no
textField.keyboardType = .emailAddress
textField.translatesAutoresizingMaskIntoConstraints = false
return textField
}()
private let passwordTextField: UITextField = {
let textField = UITextField()
textField.placeholder = "密码"
textField.borderStyle = .roundedRect
textField.isSecureTextEntry = true
textField.translatesAutoresizingMaskIntoConstraints = false
return textField
}()
private let loginButton: UIButton = {
let button = UIButton(type: .system)
button.setTitle("登录", for: .normal)
button.backgroundColor = .systemBlue
button.setTitleColor(.white, for: .normal)
button.layer.cornerRadius = 10
button.titleLabel?.font = UIFont.systemFont(ofSize: 16, weight: .bold)
button.translatesAutoresizingMaskIntoConstraints = false
return button
}()
private let biometricLoginButton: UIButton = {
let button = UIButton(type: .system)
button.backgroundColor = .systemGray6
button.setTitleColor(.label, for: .normal)
button.layer.cornerRadius = 10
button.titleLabel?.font = UIFont.systemFont(ofSize: 14, weight: .medium)
button.translatesAutoresizingMaskIntoConstraints = false
button.isHidden = true
return button
}()
private let forgotPasswordButton: UIButton = {
let button = UIButton(type: .system)
button.setTitle("忘记密码?", for: .normal)
button.setTitleColor(.systemGray, for: .normal)
button.titleLabel?.font = UIFont.systemFont(ofSize: 14)
button.translatesAutoresizingMaskIntoConstraints = false
return button
}()
private let registerButton: UIButton = {
let button = UIButton(type: .system)
let attributedTitle = NSAttributedString(
string: "没有账号? 立即注册",
attributes: [
.font: UIFont.systemFont(ofSize: 14, weight: .medium),
.foregroundColor: UIColor.systemBlue
]
)
button.setAttributedTitle(attributedTitle, for: .normal)
button.translatesAutoresizingMaskIntoConstraints = false
return button
}()
private let activityIndicator: UIActivityIndicatorView = {
let indicator = UIActivityIndicatorView(style: .medium)
indicator.color = .white
indicator.hidesWhenStopped = true
indicator.translatesAutoresizingMaskIntoConstraints = false
return indicator
}()
private let errorLabel: UILabel = {
let label = UILabel()
label.textColor = .systemRed
label.font = UIFont.systemFont(ofSize: 12, weight: .medium)
label.textAlignment = .center
label.numberOfLines = 0
label.isHidden = true
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
// MARK: - Properties
private var isLoggingIn = false
// MARK: - Lifecycle
override func viewDidLoad() {
super.viewDidLoad()
setupUI()
setupConstraints()
setupActions()
setupTapGesture()
setupKeyboardNotifications()
setupBiometricButton()
checkNetworkStatus()
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
// 自动聚焦到用户名输入框
usernameTextField.becomeFirstResponder()
}
// MARK: - Setup Methods
private func setupUI() {
view.backgroundColor = .systemGroupedBackground
// 添加背景图片
view.addSubview(backgroundImage)
// 添加容器视图
view.addSubview(containerView)
containerView.addSubview(titleLabel)
containerView.addSubview(subtitleLabel)
containerView.addSubview(usernameTextField)
containerView.addSubview(passwordTextField)
containerView.addSubview(loginButton)
containerView.addSubview(biometricLoginButton)
containerView.addSubview(forgotPasswordButton)
containerView.addSubview(activityIndicator)
containerView.addSubview(errorLabel)
view.addSubview(registerButton)
// 设置输入框样式
[usernameTextField, passwordTextField].forEach { textField in
textField?.backgroundColor = .systemBackground
textField?.layer.cornerRadius = 8
textField?.layer.borderWidth = 1
textField?.layer.borderColor = UIColor.systemGray5.cgColor
textField?.leftView = UIView(frame: CGRect(x: 0, y: 0, width: 12, height: 0))
textField?.leftViewMode = .always
}
}
private func setupConstraints() {
NSLayoutConstraint.activate([
// 背景图片
backgroundImage.centerXAnchor.constraint(equalTo: view.centerXAnchor),
backgroundImage.centerYAnchor.constraint(equalTo: view.centerYAnchor),
backgroundImage.widthAnchor.constraint(equalToConstant: 200),
backgroundImage.heightAnchor.constraint(equalToConstant: 200),
// 容器视图
containerView.centerXAnchor.constraint(equalTo: view.centerXAnchor),
containerView.centerYAnchor.constraint(equalTo: view.centerYAnchor),
containerView.widthAnchor.constraint(equalToConstant: 320),
containerView.heightAnchor.constraint(equalToConstant: 420),
// 标题
titleLabel.topAnchor.constraint(equalTo: containerView.topAnchor, constant: 24),
titleLabel.leadingAnchor.constraint(equalTo: containerView.leadingAnchor, constant: 20),
titleLabel.trailingAnchor.constraint(equalTo: containerView.trailingAnchor, constant: -20),
// 副标题
subtitleLabel.topAnchor.constraint(equalTo: titleLabel.bottomAnchor, constant: 4),
subtitleLabel.leadingAnchor.constraint(equalTo: containerView.leadingAnchor, constant: 20),
subtitleLabel.trailingAnchor.constraint(equalTo: containerView.trailingAnchor, constant: -20),
// 用户名输入框
usernameTextField.topAnchor.constraint(equalTo: subtitleLabel.bottomAnchor, constant: 24),
usernameTextField.leadingAnchor.constraint(equalTo: containerView.leadingAnchor, constant: 20),
usernameTextField.trailingAnchor.constraint(equalTo: containerView.trailingAnchor, constant: -20),
usernameTextField.heightAnchor.constraint(equalToConstant: 44),
// 密码输入框
passwordTextField.topAnchor.constraint(equalTo: usernameTextField.bottomAnchor, constant: 12),
passwordTextField.leadingAnchor.constraint(equalTo: containerView.leadingAnchor, constant: 20),
passwordTextField.trailingAnchor.constraint(equalTo: containerView.trailingAnchor, constant: -20),
passwordTextField.heightAnchor.constraint(equalToConstant: 44),
// 登录按钮
loginButton.topAnchor.constraint(equalTo: passwordTextField.bottomAnchor, constant: 20),
loginButton.leadingAnchor.constraint(equalTo: containerView.leadingAnchor, constant: 20),
loginButton.trailingAnchor.constraint(equalTo: containerView.trailingAnchor, constant: -20),
loginButton.heightAnchor.constraint(equalToConstant: 44),
// 生物识别按钮
biometricLoginButton.topAnchor.constraint(equalTo: loginButton.bottomAnchor, constant: 8),
biometricLoginButton.leadingAnchor.constraint(equalTo: containerView.leadingAnchor, constant: 20),
biometricLoginButton.trailingAnchor.constraint(equalTo: containerView.trailingAnchor, constant: -20),
biometricLoginButton.heightAnchor.constraint(equalToConstant: 44),
// 忘记密码按钮
forgotPasswordButton.topAnchor.constraint(equalTo: biometricLoginButton.bottomAnchor, constant: 12),
forgotPasswordButton.centerXAnchor.constraint(equalTo: containerView.centerXAnchor),
forgotPasswordButton.heightAnchor.constraint(equalToConstant: 20),
// 活动指示器
activityIndicator.centerXAnchor.constraint(equalTo: loginButton.centerXAnchor),
activityIndicator.centerYAnchor.constraint(equalTo: loginButton.centerYAnchor),
// 错误标签
errorLabel.topAnchor.constraint(equalTo: forgotPasswordButton.bottomAnchor, constant: 8),
errorLabel.leadingAnchor.constraint(equalTo: containerView.leadingAnchor, constant: 20),
errorLabel.trailingAnchor.constraint(equalTo: containerView.trailingAnchor, constant: -20),
errorLabel.heightAnchor.constraint(greaterThanOrEqualToConstant: 20),
// 注册按钮
registerButton.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor, constant: -20),
registerButton.centerXAnchor.constraint(equalTo: view.centerXAnchor),
registerButton.heightAnchor.constraint(equalToConstant: 20)
])
}
private func setupActions() {
loginButton.addTarget(self, action: #selector(loginButtonTapped), for: .touchUpInside)
biometricLoginButton.addTarget(self, action: #selector(biometricLoginTapped), for: .touchUpInside)
forgotPasswordButton.addTarget(self, action: #selector(forgotPasswordTapped), for: .touchUpInside)
registerButton.addTarget(self, action: #selector(registerTapped), for: .touchUpInside)
}
private func setupTapGesture() {
let tap = UITapGestureRecognizer(target: self, action: #selector(dismissKeyboard))
tap.cancelsTouchesInView = false
view.addGestureRecognizer(tap)
}
private func setupKeyboardNotifications() {
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name: UIResponder.keyboardWillShowNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name: UIResponder.keyboardWillHideNotification, object: nil)
}
private func setupBiometricButton() {
if BiometricAuthManager.shared.isBiometricAvailable() {
biometricLoginButton.isHidden = false
let biometricType = BiometricAuthManager.shared.getBiometricType()
biometricLoginButton.setTitle("使用\(biometricType)登录", for: .normal)
}
}
private func checkNetworkStatus() {
let monitor = NWPathMonitor()
monitor.pathUpdateHandler = { [weak self] path in
DispatchQueue.main.async {
if path.status != .satisfied {
self?.showError("网络不可用，请检查网络连接")
}
}
}
monitor.start(queue: DispatchQueue(label: "NetworkMonitor"))
}
// MARK: - Action Methods
@objc private func loginButtonTapped() {
performLogin()
}
@objc private func biometricLoginTapped() {
BiometricAuthManager.shared.authenticate { [weak self] success, error in
if success {
self?.handleBiometricLogin()
} else {
self?.showError(error?.localizedDescription ?? "生物识别验证失败")
}
}
}
@objc private func forgotPasswordTapped() {
// 跳转到忘记密码界面
let forgotVC = ForgotPasswordViewController()
present(forgotVC, animated: true)
}
@objc private func registerTapped() {
// 跳转到注册界面
let registerVC = RegisterViewController()
present(registerVC, animated: true)
}
@objc private func dismissKeyboard() {
view.endEditing(true)
}
// MARK: - Login Logic
private func performLogin() {
guard !isLoggingIn else { return }
dismissKeyboard()
errorLabel.isHidden = true
guard let username = usernameTextField.text,
let password = passwordTextField.text else {
showError("输入框不能为空")
return
}
// 验证输入
let usernameValidation: InputValidator.ValidationResult
if username.contains("@") {
usernameValidation = InputValidator.validateEmail(username)
} else {
usernameValidation = InputValidator.validateUsername(username)
}
guard usernameValidation.isValid else {
showError(usernameValidation.errorMessage ?? "用户名格式错误")
return
}
let passwordValidation = InputValidator.validatePassword(password)
guard passwordValidation.isValid else {
showError(passwordValidation.errorMessage ?? "密码格式错误")
return
}
// 执行登录
executeLoginRequest(
username: usernameValidation.value!,
password: passwordValidation.value!
)
}
private func executeLoginRequest(username: String, password: String) {
isLoggingIn = true
setLoadingState(true)
Task {
do {
let response = try await NetworkManager.shared.requestWithRetry(
endpoint: "https://api.example.com/auth/login",
method: "POST",
parameters: [
"username": username,
"password": password,
"device_info": getDeviceInfo()
],
headers: [
"User-Agent": "MyApp/1.0 (iOS)",
"Accept": "application/json"
],
responseType: LoginResponse.self,
maxRetries: 2
)
await MainActor.run {
handleLoginResponse(response, username: username)
}
} catch let error as NetworkError {
await MainActor.run {
handleNetworkError(error)
}
} catch {
await MainActor.run {
showError("未知错误: \(error.localizedDescription)")
}
}
}
}
private func handleLoginResponse(_ response: LoginResponse, username: String) {
isLoggingIn = false
setLoadingState(false)
if response.success, let token = response.token {
TokenManager.shared.saveToken(token)
OfflineCacheManager.shared.saveLastLogin(username: username)
if let user = response.user {
// 保存用户信息
saveUserInfo(user)
}
navigateToMainScreen()
} else {
showError(response.message ?? "登录失败")
}
}
private func handleBiometricLogin() {
// 从Keychain获取token
guard let token = TokenManager.shared.getToken() else {
showError("请先进行一次密码登录")
return
}
// 验证token是否有效（可选）
validateToken(token) { [weak self] isValid in
if isValid {
self?.navigateToMainScreen()
} else {
self?.showError("登录已过期，请重新登录")
}
}
}
private func validateToken(_ token: String, completion: @escaping (Bool) -> Void) {
// 这里可以调用一个简单的API来验证token
// 为了演示，我们假设token有效
completion(true)
}
private func handleNetworkError(_ error: NetworkError) {
isLoggingIn = false
setLoadingState(false)
switch error {
case .networkUnavailable:
showError("网络不可用，请检查网络连接")
case .timeout:
showError("请求超时，请稍后重试")
case .unauthorized:
showError("用户名或密码错误")
case .serverError(let code):
showError("服务器错误 (代码: \(code))")
default:
showError(error.localizedDescription)
}
}
// MARK: - UI Updates
private func setLoadingState(_ isLoading: Bool) {
if isLoading {
loginButton.setTitle("", for: .normal)
activityIndicator.startAnimating()
loginButton.isEnabled = false
biometricLoginButton.isEnabled = false
usernameTextField.isEnabled = false
passwordTextField.isEnabled = false
} else {
activityIndicator.stopAnimating()
loginButton.setTitle("登录", for: .normal)
loginButton.isEnabled = true
biometricLoginButton.isEnabled = true
usernameTextField.isEnabled = true
passwordTextField.isEnabled = true
}
}
private func showError(_ message: String) {
errorLabel.text = message
errorLabel.isHidden = false
// 动画效果
errorLabel.transform = CGAffineTransform(scaleX: 0.9, y: 0.9)
UIView.animate(withDuration: 0.3, delay: 0, usingSpringWithDamping: 0.7, initialSpringVelocity: 0.5) {
self.errorLabel.transform = .identity
self.view.layoutIfNeeded()
}
}
// MARK: - Navigation
private func navigateToMainScreen() {
let mainVC = MainViewController()
mainVC.modalPresentationStyle = .fullScreen
if let window = view.window {
UIView.transition(with: window, duration: 0.5, options: .transitionCrossDissolve) {
window.rootViewController = mainVC
}
}
}
// MARK: - Keyboard Handling
@objc private func keyboardWillShow(notification: NSNotification) {
guard let userInfo = notification.userInfo,
let keyboardFrame = userInfo[UIResponder.keyboardFrameEndUserInfoKey] as? CGRect,
let duration = userInfo[UIResponder.keyboardAnimationDurationUserInfoKey] as? Double else {
return
}
let keyboardHeight = keyboardFrame.height
// 只在容器视图被遮挡时调整
let containerBottom = containerView.frame.maxY
let viewHeight = view.frame.height
let safeAreaBottom = view.safeAreaInsets.bottom
if containerBottom > viewHeight - keyboardHeight - safeAreaBottom {
UIView.animate(withDuration: duration) {
self.containerView.transform = CGAffineTransform(translationX: 0, y: -(keyboardHeight / 2))
}
}
}
@objc private func keyboardWillHide(notification: NSNotification) {
guard let userInfo = notification.userInfo,
let duration = userInfo[UIResponder.keyboardAnimationDurationUserInfoKey] as? Double else {
return
}
UIView.animate(withDuration: duration) {
self.containerView.transform = .identity
}
}
// MARK: - Helper Methods
private func getDeviceInfo() -> [String: String] {
return [
"platform": "iOS",
"device_model": UIDevice.current.model,
"system_version": UIDevice.current.systemVersion,
"app_version": Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String ?? "1.0"
]
}
private func saveUserInfo(_ user: User) {
let userInfo: [String: String] = [
"id": user.id,
"username": user.username,
"email": user.email,
"createdAt": user.createdAt
]
UserDefaults.standard.set(userInfo, forKey: "current_user")
}
deinit {
NotificationCenter.default.removeObserver(self)
}
}
5.2 辅助视图控制器
为了完整性，提供简单的辅助视图：
// 忘记密码视图控制器
class ForgotPasswordViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .systemBackground
let label = UILabel()
label.text = "忘记密码功能"
label.textAlignment = .center
label.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(label)
NSLayoutConstraint.activate([
label.centerXAnchor.constraint(equalTo: view.centerXAnchor),
label.centerYAnchor.constraint(equalTo: view.centerYAnchor)
])
}
}
// 注册视图控制器
class RegisterViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .systemBackground
let label = UILabel()
label.text = "注册功能"
label.textAlignment = .center
label.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(label)
NSLayoutConstraint.activate([
label.centerXAnchor.constraint(equalTo: view.centerXAnchor),
label.centerYAnchor.constraint(equalTo: view.centerYAnchor)
])
}
}
// 主界面视图控制器
class MainViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .systemBackground
let label = UILabel()
label.text = "登录成功！这是主界面"
label.textAlignment = .center
label.font = UIFont.systemFont(ofSize: 24, weight: .bold)
label.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(label)
NSLayoutConstraint.activate([
label.centerXAnchor.constraint(equalTo: view.centerXAnchor),
label.centerYAnchor.constraint(equalTo: view.centerYAnchor)
])
}
}
6. 测试与优化建议
6.1 单元测试示例
为验证逻辑编写测试：
import XCTest
@testable import YourApp
class InputValidatorTests: XCTestCase {
func testValidUsername() {
let result = InputValidator.validateUsername("user123")
XCTAssertTrue(result.isValid)
XCTAssertEqual(result.value, "user123")
}
func testInvalidUsernameTooShort() {
let result = InputValidator.validateUsername("ab")
XCTAssertFalse(result.isValid)
XCTAssertEqual(result.errorMessage, "用户名至少需要3个字符")
}
func testValidEmail() {
let result = InputValidator.validateEmail("test@example.com")
XCTAssertTrue(result.isValid)
}
func testInvalidEmail() {
let result = InputValidator.validateEmail("invalid-email")
XCTAssertFalse(result.isValid)
}
func testValidPassword() {
let result = InputValidator.validatePassword("password123")
XCTAssertTrue(result.isValid)
}
func testInvalidPasswordTooShort() {
let result = InputValidator.validatePassword("pass1")
XCTAssertFalse(result.isValid)
XCTAssertEqual(result.errorMessage, "密码至少需要8个字符")
}
}
6.2 性能优化建议
图片优化: 使用SF Symbols代替自定义图片
内存管理: 使用weak self避免循环引用
网络优化: 实现请求缓存，减少不必要的网络调用
UI渲染: 使用shouldRasterize优化复杂视图层次
6.3 安全最佳实践
始终使用HTTPS: 确保所有API调用使用SSL/TLS
输入清理: 在发送到服务器前清理所有输入
错误信息: 不要向用户暴露过多技术细节
速率限制: 在服务器端实现登录尝试限制
Token刷新: 实现自动token刷新机制
7. 总结
本教程详细介绍了如何使用Swift构建一个完整的iOS登录界面，涵盖了从UI设计到安全实现的各个方面。关键要点包括：
美观的UI: 使用Auto Layout和现代UI设计原则
严格的验证: 客户端和服务器端双重验证
安全的网络请求: 使用Keychain存储token，实现重试机制
用户体验: 处理键盘遮挡、加载状态、错误提示
高级功能: 生物识别登录、离线缓存、网络状态检查
通过这些实践，你可以创建一个既安全又用户友好的登录界面，为你的应用打下坚实的基础。记住，安全是一个持续的过程，需要定期更新和审查你的实现。