在iOS应用开发中，选择合适的架构设计模式对于构建可维护、可测试和可扩展的应用至关重要。本文将深入探讨iOS开发中常用的架构模式，包括MVC、MVP、MVVM和VIPER，分析它们的优缺点，并提供实际的代码示例和最佳实践。
架构设计模式概述
为什么需要架构设计模式
1. 代码组织
将代码按照职责分离，提高可读性
降低模块间的耦合度
便于团队协作开发
2. 可维护性
易于修改和扩展功能
减少bug的产生
提高代码质量
3. 可测试性
支持单元测试
便于模拟和隔离测试
提高测试覆盖率
4. 可扩展性
支持功能的快速迭代
便于添加新特性
适应业务需求变化
架构模式选择原则
@interface ArchitectureEvaluator : NSObject
// 评估标准
@property (nonatomic, assign) NSInteger teamSize;
@property (nonatomic, assign) NSInteger projectComplexity;
@property (nonatomic, assign) NSInteger testingRequirement;
@property (nonatomic, assign) NSInteger maintenanceRequirement;
@property (nonatomic, assign) NSInteger developmentSpeed;
- (NSString *)recommendedArchitecture;
- (NSDictionary *)evaluateArchitectures;
@end
@implementation ArchitectureEvaluator
- (NSString *)recommendedArchitecture {
NSDictionary *scores = [self evaluateArchitectures];
NSString *bestArchitecture = nil;
NSInteger highestScore = 0;
for (NSString *architecture in scores.allKeys) {
NSInteger score = [scores[architecture] integerValue];
if (score > highestScore) {
highestScore = score;
bestArchitecture = architecture;
}
}
return bestArchitecture;
}
- (NSDictionary *)evaluateArchitectures {
NSMutableDictionary *scores = [NSMutableDictionary dictionary];
// MVC评分
NSInteger mvcScore = 0;
if (_teamSize <= 3) mvcScore += 2;
if (_projectComplexity <= 3) mvcScore += 2;
if (_developmentSpeed >= 4) mvcScore += 2;
scores[@"MVC"] = @(mvcScore);
// MVP评分
NSInteger mvpScore = 0;
if (_teamSize <= 5) mvpScore += 1;
if (_testingRequirement >= 3) mvpScore += 2;
if (_projectComplexity >= 3) mvpScore += 1;
scores[@"MVP"] = @(mvpScore);
// MVVM评分
NSInteger mvvmScore = 0;
if (_testingRequirement >= 4) mvvmScore += 2;
if (_maintenanceRequirement >= 4) mvvmScore += 2;
if (_projectComplexity >= 4) mvvmScore += 1;
scores[@"MVVM"] = @(mvvmScore);
// VIPER评分
NSInteger viperScore = 0;
if (_teamSize >= 5) viperScore += 2;
if (_projectComplexity >= 4) viperScore += 2;
if (_maintenanceRequirement >= 4) viperScore += 1;
if (_testingRequirement >= 4) viperScore += 1;
scores[@"VIPER"] = @(viperScore);
return scores;
}
@end
5. Router实现
// UserListRouter.h
@interface UserListRouter : NSObject
@property (nonatomic, weak) UIViewController *viewController;
@end
// UserListRouter.m
@implementation UserListRouter
- (void)navigateToUserDetail:(UserEntity *)user {
// 创建用户详情模块
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
UIViewController *userDetailVC = [storyboard instantiateViewControllerWithIdentifier:@"UserDetailViewController"];
// 传递用户数据
// [userDetailVC configureWithUser:user];
[self.viewController.navigationController pushViewController:userDetailVC animated:YES];
}
- (void)navigateToAddUser {
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
UIViewController *addUserVC = [storyboard instantiateViewControllerWithIdentifier:@"AddUserViewController"];
UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:addUserVC];
[self.viewController presentViewController:navController animated:YES completion:nil];
}
@end
6. View实现
// UserListVIPERViewController.h
@interface UserListVIPERViewController : UIViewController
@property (nonatomic, weak) IBOutlet UITableView *tableView;
@property (nonatomic, weak) IBOutlet UIActivityIndicatorView *loadingIndicator;
@property (nonatomic, strong) id
@end
// UserListVIPERViewController.m
@implementation UserListVIPERViewController
- (void)viewDidLoad {
[super viewDidLoad];
[self setupUI];
[self setupTableView];
[self.presenter viewDidLoad];
}
- (void)setupUI {
self.title = @"Users (VIPER)";
UIBarButtonItem *refreshButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemRefresh
target:self
action:@selector(refreshUsers)];
UIBarButtonItem *addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd
target:self
action:@selector(addUser)];
self.navigationItem.rightBarButtonItems = @[addButton, refreshButton];
}
- (void)setupTableView {
self.tableView.delegate = self;
self.tableView.dataSource = self;
UINib *cellNib = [UINib nibWithNibName:@"UserTableViewCell" bundle:nil];
[self.tableView registerNib:cellNib forCellReuseIdentifier:@"UserTableViewCell"];
self.tableView.rowHeight = 80;
self.tableView.estimatedRowHeight = 80;
UIRefreshControl *refreshControl = [[UIRefreshControl alloc] init];
[refreshControl addTarget:self action:@selector(refreshUsers) forControlEvents:UIControlEventValueChanged];
self.tableView.refreshControl = refreshControl;
}
- (void)refreshUsers {
[self.presenter refreshUsers];
}
- (void)addUser {
UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"Add User"
message:@"Enter user information"
preferredStyle:UIAlertControllerStyleAlert];
[alert addTextFieldWithConfigurationHandler:^(UITextField *textField) {
textField.placeholder = @"Username";
}];
[alert addTextFieldWithConfigurationHandler:^(UITextField *textField) {
textField.placeholder = @"Email";
textField.keyboardType = UIKeyboardTypeEmailAddress;
}];
UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:@"Cancel"
style:UIAlertActionStyleCancel
handler:nil];
UIAlertAction *addAction = [UIAlertAction actionWithTitle:@"Add"
style:UIAlertActionStyleDefault
handler:^(UIAlertAction *action) {
NSString *username = alert.textFields[0].text;
NSString *email = alert.textFields[1].text;
[self.presenter addUserWithUsername:username email:email];
}];
[alert addAction:cancelAction];
[alert addAction:addAction];
[self presentViewController:alert animated:YES completion:nil];
}
#pragma mark - UserListViewProtocol
- (void)showUsers:(NSArray
[self.tableView reloadData];
}
- (void)showLoading:(BOOL)loading {
if (loading) {
[self.loadingIndicator startAnimating];
} else {
[self.loadingIndicator stopAnimating];
[self.tableView.refreshControl endRefreshing];
}
self.tableView.userInteractionEnabled = !loading;
}
- (void)showError:(NSString *)errorMessage {
UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"Error"
message:errorMessage
preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction *okAction = [UIAlertAction actionWithTitle:@"OK"
style:UIAlertActionStyleDefault
handler:nil];
[alert addAction:okAction];
[self presentViewController:alert animated:YES completion:nil];
}
- (void)showUserAdded {
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:[self.presenter numberOfUsers] - 1 inSection:0];
[self.tableView insertRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
}
- (void)showUserDeleted {
[self.tableView reloadData];
}
#pragma mark - UITableViewDataSource
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return [self.presenter numberOfUsers];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UserTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"UserTableViewCell" forIndexPath:indexPath];
UserEntity *userEntity = [self.presenter userAtIndex:indexPath.row];
User *user = [userEntity toUser];
[cell configureWithUser:user];
return cell;
}
#pragma mark - UITableViewDelegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
[tableView deselectRowAtIndexPath:indexPath animated:YES];
[self.presenter selectUserAtIndex:indexPath.row];
}
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath {
return YES;
}
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
if (editingStyle == UITableViewCellEditingStyleDelete) {
UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"Delete User"
message:@"Are you sure you want to delete this user?"
preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:@"Cancel"
style:UIAlertActionStyleCancel
handler:nil];
UIAlertAction *deleteAction = [UIAlertAction actionWithTitle:@"Delete"
style:UIAlertActionStyleDestructive
handler:^(UIAlertAction *action) {
[self.presenter deleteUserAtIndex:indexPath.row];
}];
[alert addAction:cancelAction];
[alert addAction:deleteAction];
[self presentViewController:alert animated:YES completion:nil];
}
}
@end
7. 模块装配器
// UserListVIPERAssembler.h
@interface UserListVIPERAssembler : NSObject
+ (UIViewController *)assembleUserListModule;
@end
// UserListVIPERAssembler.m
@implementation UserListVIPERAssembler
+ (UIViewController *)assembleUserListModule {
// 创建各个组件
UserListVIPERViewController *view = [[UserListVIPERViewController alloc] init];
UserListPresenter *presenter = [[UserListPresenter alloc] init];
UserListInteractor *interactor = [[UserListInteractor alloc] init];
UserListRouter *router = [[UserListRouter alloc] init];
// 建立连接
view.presenter = presenter;
presenter.view = view;
presenter.interactor = interactor;
presenter.router = router;
interactor.output = presenter;
router.viewController = view;
return view;
}
@end
VIPER优缺点分析
优点：
职责分离非常清晰
高度可测试性
易于团队协作开发
支持复杂业务逻辑
导航逻辑独立管理
缺点：
代码量大，开发复杂度高
学习成本高
过度设计，适合大型项目
需要大量的协议定义
调试相对困难
架构模式对比分析
复杂度对比
@interface ArchitectureComplexityAnalyzer : NSObject
+ (NSDictionary *)analyzeComplexity;
+ (NSString *)recommendArchitectureForProjectSize:(NSInteger)projectSize
teamSize:(NSInteger)teamSize
complexity:(NSInteger)complexity;
@end
@implementation ArchitectureComplexityAnalyzer
+ (NSDictionary *)analyzeComplexity {
return @{
@"MVC": @{
@"learning_curve": @1,
@"code_volume": @1,
@"testability": @2,
@"maintainability": @2,
@"scalability": @2
},
@"MVP": @{
@"learning_curve": @2,
@"code_volume": @2,
@"testability": @4,
@"maintainability": @3,
@"scalability": @3
},
@"MVVM": @{
@"learning_curve": @3,
@"code_volume": @3,
@"testability": @4,
@"maintainability": @4,
@"scalability": @4
},
@"VIPER": @{
@"learning_curve": @4,
@"code_volume": @4,
@"testability": @5,
@"maintainability": @5,
@"scalability": @5
}
};
}
+ (NSString *)recommendArchitectureForProjectSize:(NSInteger)projectSize
teamSize:(NSInteger)teamSize
complexity:(NSInteger)complexity {
NSInteger totalScore = projectSize + teamSize + complexity;
if (totalScore <= 6) {
return @"MVC";
} else if (totalScore <= 9) {
return @"MVP";
} else if (totalScore <= 12) {
return @"MVVM";
} else {
return @"VIPER";
}
}
@end
性能对比
架构模式
内存占用
CPU开销
启动时间
运行效率
MVC
低
低
快
高
MVP
中
中
中
中
MVVM
中高
中高
中
中
VIPER
高
高
慢
中低
适用场景分析
MVC适用场景：
小型项目（< 20个页面）
快速原型开发
团队规模小（1-3人）
简单的业务逻辑
MVP适用场景：
中小型项目（20-50个页面）
需要单元测试
团队规模中等（3-5人）
中等复杂度业务逻辑
MVVM适用场景：
中大型项目（50-100个页面）
复杂的数据绑定需求
团队有响应式编程经验
需要高度可测试性
VIPER适用场景：
大型企业级项目（> 100个页面）
复杂的业务逻辑
大型团队（> 5人）
长期维护项目
架构设计最佳实践
1. 渐进式架构演进
@interface ArchitectureEvolutionManager : NSObject
@property (nonatomic, strong) NSString *currentArchitecture;
@property (nonatomic, strong) NSArray
- (void)planEvolution:(NSString *)targetArchitecture;
- (BOOL)canEvolveToArchitecture:(NSString *)architecture;
- (NSArray
@end
@implementation ArchitectureEvolutionManager
- (instancetype)init {
self = [super init];
if (self) {
_currentArchitecture = @"MVC";
_evolutionPath = @[@"MVC", @"MVP", @"MVVM", @"VIPER"];
}
return self;
}
- (void)planEvolution:(NSString *)targetArchitecture {
NSArray
NSLog(@"Architecture Evolution Plan:");
for (NSInteger i = 0; i < steps.count; i++) {
NSLog(@"Step %ld: %@", (long)(i + 1), steps[i]);
}
}
- (BOOL)canEvolveToArchitecture:(NSString *)architecture {
NSInteger currentIndex = [self.evolutionPath indexOfObject:self.currentArchitecture];
NSInteger targetIndex = [self.evolutionPath indexOfObject:architecture];
return targetIndex > currentIndex;
}
- (NSArray
NSInteger currentIndex = [self.evolutionPath indexOfObject:self.currentArchitecture];
NSInteger targetIndex = [self.evolutionPath indexOfObject:targetArchitecture];
if (targetIndex <= currentIndex) {
return @[];
}
NSRange range = NSMakeRange(currentIndex + 1, targetIndex - currentIndex);
return [self.evolutionPath subarrayWithRange:range];
}
@end
2. 架构质量评估
@interface ArchitectureQualityAssessment : NSObject
- (NSDictionary *)assessCodebase:(NSString *)projectPath;
- (NSInteger)calculateMaintainabilityIndex:(NSDictionary *)metrics;
- (NSArray
- (NSDictionary *)generateImprovementSuggestions:(NSDictionary *)assessment;
@end
@implementation ArchitectureQualityAssessment
- (NSDictionary *)assessCodebase:(NSString *)projectPath {
// 模拟代码质量评估
return @{
@"coupling": @{
@"score": @75,
@"threshold": @80,
@"status": @"good"
},
@"cohesion": @{
@"score": @85,
@"threshold": @80,
@"status": @"excellent"
},
@"complexity": @{
@"score": @65,
@"threshold": @70,
@"status": @"warning"
},
@"testability": @{
@"score": @70,
@"threshold": @75,
@"status": @"warning"
},
@"maintainability": @{
@"score": @78,
@"threshold": @75,
@"status": @"good"
}
};
}
- (NSInteger)calculateMaintainabilityIndex:(NSDictionary *)metrics {
NSInteger coupling = [metrics[@"coupling"][@"score"] integerValue];
NSInteger cohesion = [metrics[@"cohesion"][@"score"] integerValue];
NSInteger complexity = [metrics[@"complexity"][@"score"] integerValue];
NSInteger testability = [metrics[@"testability"][@"score"] integerValue];
return (coupling + cohesion + complexity + testability) / 4;
}
- (NSArray
NSMutableArray
if ([metrics[@"coupling"][@"score"] integerValue] < 70) {
[smells addObject:@"High Coupling - Consider dependency injection"];
}
if ([metrics[@"cohesion"][@"score"] integerValue] < 70) {
[smells addObject:@"Low Cohesion - Review single responsibility principle"];
}
if ([metrics[@"complexity"][@"score"] integerValue] < 60) {
[smells addObject:@"High Complexity - Consider breaking down large classes"];
}
if ([metrics[@"testability"][@"score"] integerValue] < 60) {
[smells addObject:@"Poor Testability - Increase dependency injection usage"];
}
return [smells copy];
}
- (NSDictionary *)generateImprovementSuggestions:(NSDictionary *)assessment {
NSMutableDictionary *suggestions = [NSMutableDictionary dictionary];
for (NSString *metric in assessment.allKeys) {
NSDictionary *metricData = assessment[metric];
NSString *status = metricData[@"status"];
if ([status isEqualToString:@"warning"] || [status isEqualToString:@"critical"]) {
if ([metric isEqualToString:@"coupling"]) {
suggestions[metric] = @"Implement dependency injection and use protocols for abstraction";
} else if ([metric isEqualToString:@"complexity"]) {
suggestions[metric] = @"Break down large classes and methods, apply single responsibility principle";
} else if ([metric isEqualToString:@"testability"]) {
suggestions[metric] = @"Increase unit test coverage and use mock objects for dependencies";
}
}
}
return [suggestions copy];
}
@end
总结
在iOS应用开发中，选择合适的架构设计模式对于项目的成功至关重要。每种架构模式都有其适用的场景和优缺点：
关键要点：
MVC：适合小型项目和快速开发，但容易导致Controller臃肿
MVP：通过Presenter分离业务逻辑，提高可测试性
MVVM：利用数据绑定机制，适合复杂的UI交互场景
VIPER：最细粒度的职责分离，适合大型企业级项目
最佳实践建议：
渐进式演进：从简单架构开始，随着项目复杂度增长逐步演进
团队能力匹配：选择团队能够掌握和维护的架构模式
项目特点考虑：根据项目规模、复杂度和维护周期选择合适架构
质量持续监控：定期评估架构质量，及时重构和优化
文档和培训：确保团队成员理解架构设计原则和实现细节
通过合理选择和实施架构设计模式，可以显著提高iOS应用的代码质量、可维护性和开发效率，为项目的长期成功奠定坚实基础。
MVC架构模式
MVC基本原理
MVC（Model-View-Controller）是iOS开发中最传统的架构模式，将应用分为三个核心组件：
Model：数据模型和业务逻辑
View：用户界面展示
Controller：协调Model和View的交互
MVC实现示例
1. Model层实现
// User.h
@interface User : NSObject
@property (nonatomic, strong) NSString *userId;
@property (nonatomic, strong) NSString *username;
@property (nonatomic, strong) NSString *email;
@property (nonatomic, strong) NSDate *createdAt;
@property (nonatomic, assign) BOOL isActive;
- (instancetype)initWithDictionary:(NSDictionary *)dictionary;
- (NSDictionary *)toDictionary;
- (BOOL)isValidEmail;
@end
// User.m
@implementation User
- (instancetype)initWithDictionary:(NSDictionary *)dictionary {
self = [super init];
if (self) {
_userId = dictionary[@"id"];
_username = dictionary[@"username"];
_email = dictionary[@"email"];
_isActive = [dictionary[@"is_active"] boolValue];
NSString *dateString = dictionary[@"created_at"];
if (dateString) {
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
formatter.dateFormat = @"yyyy-MM-dd'T'HH:mm:ss'Z'";
_createdAt = [formatter dateFromString:dateString];
}
}
return self;
}
- (NSDictionary *)toDictionary {
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
if (_userId) dict[@"id"] = _userId;
if (_username) dict[@"username"] = _username;
if (_email) dict[@"email"] = _email;
dict[@"is_active"] = @(_isActive);
if (_createdAt) {
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
formatter.dateFormat = @"yyyy-MM-dd'T'HH:mm:ss'Z'";
dict[@"created_at"] = [formatter stringFromDate:_createdAt];
}
return dict;
}
- (BOOL)isValidEmail {
NSString *emailRegex = @"[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,64}";
NSPredicate *emailPredicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", emailRegex];
return [emailPredicate evaluateWithObject:_email];
}
@end
// UserService.h
@interface UserService : NSObject
+ (instancetype)sharedService;
- (void)fetchUsersWithCompletion:(void(^)(NSArray
- (void)createUser:(User *)user completion:(void(^)(User *user, NSError *error))completion;
- (void)updateUser:(User *)user completion:(void(^)(User *user, NSError *error))completion;
- (void)deleteUserWithId:(NSString *)userId completion:(void(^)(BOOL success, NSError *error))completion;
@end
// UserService.m
@implementation UserService
+ (instancetype)sharedService {
static UserService *sharedInstance = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
sharedInstance = [[UserService alloc] init];
});
return sharedInstance;
}
- (void)fetchUsersWithCompletion:(void(^)(NSArray
// 模拟网络请求
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1.0 * NSEC_PER_SEC)), dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
// 模拟数据
NSArray *mockData = @[
@{
@"id": @"1",
@"username": @"john_doe",
@"email": @"john@example.com",
@"is_active": @YES,
@"created_at": @"2023-01-15T10:30:00Z"
},
@{
@"id": @"2",
@"username": @"jane_smith",
@"email": @"jane@example.com",
@"is_active": @YES,
@"created_at": @"2023-02-20T14:45:00Z"
}
];
NSMutableArray *users = [NSMutableArray array];
for (NSDictionary *userData in mockData) {
User *user = [[User alloc] initWithDictionary:userData];
[users addObject:user];
}
dispatch_async(dispatch_get_main_queue(), ^{
if (completion) {
completion([users copy], nil);
}
});
});
}
- (void)createUser:(User *)user completion:(void(^)(User *user, NSError *error))completion {
// 验证用户数据
if (!user.username || user.username.length == 0) {
NSError *error = [NSError errorWithDomain:@"UserServiceError"
code:1001
userInfo:@{NSLocalizedDescriptionKey: @"Username is required"}];
if (completion) completion(nil, error);
return;
}
if (![user isValidEmail]) {
NSError *error = [NSError errorWithDomain:@"UserServiceError"
code:1002
userInfo:@{NSLocalizedDescriptionKey: @"Invalid email format"}];
if (completion) completion(nil, error);
return;
}
// 模拟网络请求
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.5 * NSEC_PER_SEC)), dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
// 模拟服务器响应
user.userId = [[NSUUID UUID] UUIDString];
user.createdAt = [NSDate date];
user.isActive = YES;
dispatch_async(dispatch_get_main_queue(), ^{
if (completion) {
completion(user, nil);
}
});
});
}
- (void)updateUser:(User *)user completion:(void(^)(User *user, NSError *error))completion {
if (!user.userId) {
NSError *error = [NSError errorWithDomain:@"UserServiceError"
code:1003
userInfo:@{NSLocalizedDescriptionKey: @"User ID is required for update"}];
if (completion) completion(nil, error);
return;
}
// 模拟网络请求
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.5 * NSEC_PER_SEC)), dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
dispatch_async(dispatch_get_main_queue(), ^{
if (completion) {
completion(user, nil);
}
});
});
}
- (void)deleteUserWithId:(NSString *)userId completion:(void(^)(BOOL success, NSError *error))completion {
if (!userId || userId.length == 0) {
NSError *error = [NSError errorWithDomain:@"UserServiceError"
code:1004
userInfo:@{NSLocalizedDescriptionKey: @"User ID is required for deletion"}];
if (completion) completion(NO, error);
return;
}
// 模拟网络请求
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.5 * NSEC_PER_SEC)), dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
dispatch_async(dispatch_get_main_queue(), ^{
if (completion) {
completion(YES, nil);
}
});
});
}
@end
2. View层实现
// UserTableViewCell.h
@interface UserTableViewCell : UITableViewCell
@property (nonatomic, weak) IBOutlet UILabel *usernameLabel;
@property (nonatomic, weak) IBOutlet UILabel *emailLabel;
@property (nonatomic, weak) IBOutlet UILabel *statusLabel;
@property (nonatomic, weak) IBOutlet UIImageView *avatarImageView;
- (void)configureWithUser:(User *)user;
@end
// UserTableViewCell.m
@implementation UserTableViewCell
- (void)awakeFromNib {
[super awakeFromNib];
[self setupUI];
}
- (void)setupUI {
// 设置头像圆角
self.avatarImageView.layer.cornerRadius = 25;
self.avatarImageView.layer.masksToBounds = YES;
self.avatarImageView.backgroundColor = [UIColor lightGrayColor];
// 设置标签样式
self.usernameLabel.font = [UIFont boldSystemFontOfSize:16];
self.emailLabel.font = [UIFont systemFontOfSize:14];
self.emailLabel.textColor = [UIColor grayColor];
self.statusLabel.font = [UIFont systemFontOfSize:12];
self.statusLabel.layer.cornerRadius = 8;
self.statusLabel.layer.masksToBounds = YES;
self.statusLabel.textAlignment = NSTextAlignmentCenter;
}
- (void)configureWithUser:(User *)user {
self.usernameLabel.text = user.username;
self.emailLabel.text = user.email;
if (user.isActive) {
self.statusLabel.text = @"Active";
self.statusLabel.backgroundColor = [UIColor greenColor];
self.statusLabel.textColor = [UIColor whiteColor];
} else {
self.statusLabel.text = @"Inactive";
self.statusLabel.backgroundColor = [UIColor redColor];
self.statusLabel.textColor = [UIColor whiteColor];
}
// 设置默认头像
self.avatarImageView.image = [UIImage imageNamed:@"default_avatar"];
}
- (void)prepareForReuse {
[super prepareForReuse];
self.usernameLabel.text = nil;
self.emailLabel.text = nil;
self.statusLabel.text = nil;
self.avatarImageView.image = nil;
}
@end
3. Controller层实现
// UserListViewController.h
@interface UserListViewController : UIViewController
@property (nonatomic, weak) IBOutlet UITableView *tableView;
@property (nonatomic, weak) IBOutlet UIActivityIndicatorView *loadingIndicator;
@property (nonatomic, strong) NSMutableArray
@property (nonatomic, strong) UserService *userService;
@end
// UserListViewController.m
@implementation UserListViewController
- (void)viewDidLoad {
[super viewDidLoad];
[self setupUI];
[self setupTableView];
[self loadUsers];
}
- (void)setupUI {
self.title = @"Users";
// 添加刷新按钮
UIBarButtonItem *refreshButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemRefresh
target:self
action:@selector(refreshUsers)];
// 添加新增按钮
UIBarButtonItem *addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd
target:self
action:@selector(addUser)];
self.navigationItem.rightBarButtonItems = @[addButton, refreshButton];
// 初始化数据
self.users = [NSMutableArray array];
self.userService = [UserService sharedService];
}
- (void)setupTableView {
self.tableView.delegate = self;
self.tableView.dataSource = self;
// 注册cell
UINib *cellNib = [UINib nibWithNibName:@"UserTableViewCell" bundle:nil];
[self.tableView registerNib:cellNib forCellReuseIdentifier:@"UserTableViewCell"];
// 设置行高
self.tableView.rowHeight = 80;
self.tableView.estimatedRowHeight = 80;
// 添加下拉刷新
UIRefreshControl *refreshControl = [[UIRefreshControl alloc] init];
[refreshControl addTarget:self action:@selector(refreshUsers) forControlEvents:UIControlEventValueChanged];
self.tableView.refreshControl = refreshControl;
}
- (void)loadUsers {
[self showLoading:YES];
[self.userService fetchUsersWithCompletion:^(NSArray
[self showLoading:NO];
if (error) {
[self showErrorAlert:error.localizedDescription];
} else {
[self.users removeAllObjects];
[self.users addObjectsFromArray:users];
[self.tableView reloadData];
}
}];
}
- (void)refreshUsers {
[self.userService fetchUsersWithCompletion:^(NSArray
[self.tableView.refreshControl endRefreshing];
if (error) {
[self showErrorAlert:error.localizedDescription];
} else {
[self.users removeAllObjects];
[self.users addObjectsFromArray:users];
[self.tableView reloadData];
}
}];
}
- (void)addUser {
UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"Add User"
message:@"Enter user information"
preferredStyle:UIAlertControllerStyleAlert];
[alert addTextFieldWithConfigurationHandler:^(UITextField *textField) {
textField.placeholder = @"Username";
}];
[alert addTextFieldWithConfigurationHandler:^(UITextField *textField) {
textField.placeholder = @"Email";
textField.keyboardType = UIKeyboardTypeEmailAddress;
}];
UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:@"Cancel"
style:UIAlertActionStyleCancel
handler:nil];
UIAlertAction *addAction = [UIAlertAction actionWithTitle:@"Add"
style:UIAlertActionStyleDefault
handler:^(UIAlertAction *action) {
NSString *username = alert.textFields[0].text;
NSString *email = alert.textFields[1].text;
if (username.length > 0 && email.length > 0) {
[self createUserWithUsername:username email:email];
} else {
[self showErrorAlert:@"Please fill in all fields"];
}
}];
[alert addAction:cancelAction];
[alert addAction:addAction];
[self presentViewController:alert animated:YES completion:nil];
}
- (void)createUserWithUsername:(NSString *)username email:(NSString *)email {
User *newUser = [[User alloc] init];
newUser.username = username;
newUser.email = email;
[self showLoading:YES];
[self.userService createUser:newUser completion:^(User *user, NSError *error) {
[self showLoading:NO];
if (error) {
[self showErrorAlert:error.localizedDescription];
} else {
[self.users addObject:user];
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:self.users.count - 1 inSection:0];
[self.tableView insertRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
}
}];
}
- (void)deleteUserAtIndexPath:(NSIndexPath *)indexPath {
User *user = self.users[indexPath.row];
[self showLoading:YES];
[self.userService deleteUserWithId:user.userId completion:^(BOOL success, NSError *error) {
[self showLoading:NO];
if (error) {
[self showErrorAlert:error.localizedDescription];
} else if (success) {
[self.users removeObjectAtIndex:indexPath.row];
[self.tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
}
}];
}
- (void)showLoading:(BOOL)show {
if (show) {
[self.loadingIndicator startAnimating];
} else {
[self.loadingIndicator stopAnimating];
}
self.tableView.userInteractionEnabled = !show;
}
- (void)showErrorAlert:(NSString *)message {
UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"Error"
message:message
preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction *okAction = [UIAlertAction actionWithTitle:@"OK"
style:UIAlertActionStyleDefault
handler:nil];
[alert addAction:okAction];
[self presentViewController:alert animated:YES completion:nil];
}
#pragma mark - UITableViewDataSource
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return self.users.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UserTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"UserTableViewCell" forIndexPath:indexPath];
User *user = self.users[indexPath.row];
[cell configureWithUser:user];
return cell;
}
#pragma mark - UITableViewDelegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
[tableView deselectRowAtIndexPath:indexPath animated:YES];
User *user = self.users[indexPath.row];
// 可以在这里导航到用户详情页面
NSLog(@"Selected user: %@", user.username);
}
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath {
return YES;
}
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
if (editingStyle == UITableViewCellEditingStyleDelete) {
UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"Delete User"
message:@"Are you sure you want to delete this user?"
preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:@"Cancel"
style:UIAlertActionStyleCancel
handler:nil];
UIAlertAction *deleteAction = [UIAlertAction actionWithTitle:@"Delete"
style:UIAlertActionStyleDestructive
handler:^(UIAlertAction *action) {
[self deleteUserAtIndexPath:indexPath];
}];
[alert addAction:cancelAction];
[alert addAction:deleteAction];
[self presentViewController:alert animated:YES completion:nil];
}
}
@end
MVC优缺点分析
优点：
简单易懂，学习成本低
开发速度快，适合小型项目
iOS原生支持，框架集成度高
代码结构清晰，职责分离明确
缺点：
Controller容易变得臃肿（Massive View Controller）
难以进行单元测试
View和Controller耦合度高
复杂业务逻辑难以维护
MVP架构模式
MVP基本原理
MVP（Model-View-Presenter）模式通过引入Presenter层来解决MVC中Controller臃肿的问题：
Model：数据模型和业务逻辑
View：用户界面展示和用户交互
Presenter：处理业务逻辑，协调Model和View
MVP实现示例
1. View协议定义
// UserListViewProtocol.h
@protocol UserListViewProtocol
- (void)showUsers:(NSArray
- (void)showLoading:(BOOL)loading;
- (void)showError:(NSString *)errorMessage;
- (void)showUserAdded:(User *)user;
- (void)showUserDeleted:(NSIndexPath *)indexPath;
- (void)refreshUserList;
@end
2. Presenter实现
// UserListPresenter.h
@interface UserListPresenter : NSObject
@property (nonatomic, weak) id
@property (nonatomic, strong) UserService *userService;
@property (nonatomic, strong) NSMutableArray
- (instancetype)initWithView:(id
- (void)viewDidLoad;
- (void)refreshUsers;
- (void)addUserWithUsername:(NSString *)username email:(NSString *)email;
- (void)deleteUserAtIndex:(NSInteger)index;
- (User *)userAtIndex:(NSInteger)index;
- (NSInteger)numberOfUsers;
@end
// UserListPresenter.m
@implementation UserListPresenter
- (instancetype)initWithView:(id
self = [super init];
if (self) {
_view = view;
_userService = [UserService sharedService];
_users = [NSMutableArray array];
}
return self;
}
- (void)viewDidLoad {
[self loadUsers];
}
- (void)loadUsers {
[self.view showLoading:YES];
[self.userService fetchUsersWithCompletion:^(NSArray
[self.view showLoading:NO];
if (error) {
[self.view showError:error.localizedDescription];
} else {
[self.users removeAllObjects];
[self.users addObjectsFromArray:users];
[self.view showUsers:[self.users copy]];
}
}];
}
- (void)refreshUsers {
[self.userService fetchUsersWithCompletion:^(NSArray
if (error) {
[self.view showError:error.localizedDescription];
} else {
[self.users removeAllObjects];
[self.users addObjectsFromArray:users];
[self.view refreshUserList];
}
}];
}
- (void)addUserWithUsername:(NSString *)username email:(NSString *)email {
// 输入验证
if (!username || username.length == 0) {
[self.view showError:@"Username is required"];
return;
}
if (!email || email.length == 0) {
[self.view showError:@"Email is required"];
return;
}
User *newUser = [[User alloc] init];
newUser.username = username;
newUser.email = email;
[self.view showLoading:YES];
[self.userService createUser:newUser completion:^(User *user, NSError *error) {
[self.view showLoading:NO];
if (error) {
[self.view showError:error.localizedDescription];
} else {
[self.users addObject:user];
[self.view showUserAdded:user];
}
}];
}
- (void)deleteUserAtIndex:(NSInteger)index {
if (index < 0 || index >= self.users.count) {
[self.view showError:@"Invalid user index"];
return;
}
User *user = self.users[index];
[self.view showLoading:YES];
[self.userService deleteUserWithId:user.userId completion:^(BOOL success, NSError *error) {
[self.view showLoading:NO];
if (error) {
[self.view showError:error.localizedDescription];
} else if (success) {
[self.users removeObjectAtIndex:index];
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:index inSection:0];
[self.view showUserDeleted:indexPath];
}
}];
}
- (User *)userAtIndex:(NSInteger)index {
if (index >= 0 && index < self.users.count) {
return self.users[index];
}
return nil;
}
- (NSInteger)numberOfUsers {
return self.users.count;
}
@end
3. View实现
// UserListMVPViewController.h
@interface UserListMVPViewController : UIViewController
@property (nonatomic, weak) IBOutlet UITableView *tableView;
@property (nonatomic, weak) IBOutlet UIActivityIndicatorView *loadingIndicator;
@property (nonatomic, strong) UserListPresenter *presenter;
@end
// UserListMVPViewController.m
@implementation UserListMVPViewController
- (void)viewDidLoad {
[super viewDidLoad];
[self setupUI];
[self setupTableView];
[self setupPresenter];
}
- (void)setupUI {
self.title = @"Users (MVP)";
UIBarButtonItem *refreshButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemRefresh
target:self
action:@selector(refreshUsers)];
UIBarButtonItem *addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd
target:self
action:@selector(addUser)];
self.navigationItem.rightBarButtonItems = @[addButton, refreshButton];
}
- (void)setupTableView {
self.tableView.delegate = self;
self.tableView.dataSource = self;
UINib *cellNib = [UINib nibWithNibName:@"UserTableViewCell" bundle:nil];
[self.tableView registerNib:cellNib forCellReuseIdentifier:@"UserTableViewCell"];
self.tableView.rowHeight = 80;
self.tableView.estimatedRowHeight = 80;
UIRefreshControl *refreshControl = [[UIRefreshControl alloc] init];
[refreshControl addTarget:self action:@selector(refreshUsers) forControlEvents:UIControlEventValueChanged];
self.tableView.refreshControl = refreshControl;
}
- (void)setupPresenter {
self.presenter = [[UserListPresenter alloc] initWithView:self];
[self.presenter viewDidLoad];
}
- (void)refreshUsers {
[self.presenter refreshUsers];
}
- (void)addUser {
UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"Add User"
message:@"Enter user information"
preferredStyle:UIAlertControllerStyleAlert];
[alert addTextFieldWithConfigurationHandler:^(UITextField *textField) {
textField.placeholder = @"Username";
}];
[alert addTextFieldWithConfigurationHandler:^(UITextField *textField) {
textField.placeholder = @"Email";
textField.keyboardType = UIKeyboardTypeEmailAddress;
}];
UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:@"Cancel"
style:UIAlertActionStyleCancel
handler:nil];
UIAlertAction *addAction = [UIAlertAction actionWithTitle:@"Add"
style:UIAlertActionStyleDefault
handler:^(UIAlertAction *action) {
NSString *username = alert.textFields[0].text;
NSString *email = alert.textFields[1].text;
[self.presenter addUserWithUsername:username email:email];
}];
[alert addAction:cancelAction];
[alert addAction:addAction];
[self presentViewController:alert animated:YES completion:nil];
}
#pragma mark - UserListViewProtocol
- (void)showUsers:(NSArray
[self.tableView reloadData];
}
- (void)showLoading:(BOOL)loading {
if (loading) {
[self.loadingIndicator startAnimating];
} else {
[self.loadingIndicator stopAnimating];
}
self.tableView.userInteractionEnabled = !loading;
}
- (void)showError:(NSString *)errorMessage {
UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"Error"
message:errorMessage
preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction *okAction = [UIAlertAction actionWithTitle:@"OK"
style:UIAlertActionStyleDefault
handler:nil];
[alert addAction:okAction];
[self presentViewController:alert animated:YES completion:nil];
}
- (void)showUserAdded:(User *)user {
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:[self.presenter numberOfUsers] - 1 inSection:0];
[self.tableView insertRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
}
- (void)showUserDeleted:(NSIndexPath *)indexPath {
[self.tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
}
- (void)refreshUserList {
[self.tableView.refreshControl endRefreshing];
[self.tableView reloadData];
}
#pragma mark - UITableViewDataSource
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return [self.presenter numberOfUsers];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UserTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"UserTableViewCell" forIndexPath:indexPath];
User *user = [self.presenter userAtIndex:indexPath.row];
[cell configureWithUser:user];
return cell;
}
#pragma mark - UITableViewDelegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
[tableView deselectRowAtIndexPath:indexPath animated:YES];
User *user = [self.presenter userAtIndex:indexPath.row];
NSLog(@"Selected user: %@", user.username);
}
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath {
return YES;
}
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
if (editingStyle == UITableViewCellEditingStyleDelete) {
UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"Delete User"
message:@"Are you sure you want to delete this user?"
preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:@"Cancel"
style:UIAlertActionStyleCancel
handler:nil];
UIAlertAction *deleteAction = [UIAlertAction actionWithTitle:@"Delete"
style:UIAlertActionStyleDestructive
handler:^(UIAlertAction *action) {
[self.presenter deleteUserAtIndex:indexPath.row];
}];
[alert addAction:cancelAction];
[alert addAction:deleteAction];
[self presentViewController:alert animated:YES completion:nil];
}
}
@end
MVP优缺点分析
优点：
业务逻辑与UI分离，便于测试
Presenter可以独立测试
View变得更加简单
代码复用性更好
缺点：
代码量增加，复杂度提升
需要定义更多的协议和接口
Presenter可能变得臃肿
学习成本相对较高
MVVM架构模式
MVVM基本原理
MVVM（Model-View-ViewModel）模式通过数据绑定机制实现View和ViewModel的自动同步：
Model：数据模型和业务逻辑
View：用户界面展示
ViewModel：视图模型，处理业务逻辑和数据绑定
MVVM实现示例
1. ViewModel实现
// UserListViewModel.h
@interface UserListViewModel : NSObject
// 数据属性
@property (nonatomic, strong, readonly) NSArray
@property (nonatomic, assign, readonly) BOOL isLoading;
@property (nonatomic, strong, readonly) NSString *errorMessage;
// 命令属性
@property (nonatomic, strong, readonly) RACCommand *loadUsersCommand;
@property (nonatomic, strong, readonly) RACCommand *refreshUsersCommand;
@property (nonatomic, strong, readonly) RACCommand *addUserCommand;
@property (nonatomic, strong, readonly) RACCommand *deleteUserCommand;
// 信号属性
@property (nonatomic, strong, readonly) RACSignal *usersSignal;
@property (nonatomic, strong, readonly) RACSignal *loadingSignal;
@property (nonatomic, strong, readonly) RACSignal *errorSignal;
- (instancetype)initWithUserService:(UserService *)userService;
- (User *)userAtIndex:(NSInteger)index;
- (NSInteger)numberOfUsers;
@end
// UserListViewModel.m
@implementation UserListViewModel {
UserService *_userService;
NSMutableArray
}
- (instancetype)initWithUserService:(UserService *)userService {
self = [super init];
if (self) {
_userService = userService;
_mutableUsers = [NSMutableArray array];
[self setupCommands];
[self setupSignals];
}
return self;
}
- (void)setupCommands {
// 加载用户命令
_loadUsersCommand = [[RACCommand alloc] initWithSignalBlock:^RACSignal *(id input) {
return [self loadUsersSignal];
}];
// 刷新用户命令
_refreshUsersCommand = [[RACCommand alloc] initWithSignalBlock:^RACSignal *(id input) {
return [self loadUsersSignal];
}];
// 添加用户命令
_addUserCommand = [[RACCommand alloc] initWithSignalBlock:^RACSignal *(NSDictionary *userInfo) {
return [self addUserSignal:userInfo];
}];
// 删除用户命令
_deleteUserCommand = [[RACCommand alloc] initWithSignalBlock:^RACSignal *(NSNumber *index) {
return [self deleteUserSignal:index.integerValue];
}];
}
- (void)setupSignals {
// 用户数据信号
_usersSignal = RACObserve(self, users);
// 加载状态信号
_loadingSignal = [RACSignal merge:@[
[self.loadUsersCommand.executing skip:1],
[self.refreshUsersCommand.executing skip:1],
[self.addUserCommand.executing skip:1],
[self.deleteUserCommand.executing skip:1]
]];
// 错误信号
_errorSignal = [RACSignal merge:@[
self.loadUsersCommand.errors,
self.refreshUsersCommand.errors,
self.addUserCommand.errors,
self.deleteUserCommand.errors
]];
}
- (RACSignal *)loadUsersSignal {
return [RACSignal createSignal:^RACDisposable *(id
[self->_userService fetchUsersWithCompletion:^(NSArray
if (error) {
[subscriber sendError:error];
} else {
[self->_mutableUsers removeAllObjects];
[self->_mutableUsers addObjectsFromArray:users];
[subscriber sendNext:[self->_mutableUsers copy]];
[subscriber sendCompleted];
}
}];
return nil;
}];
}
- (RACSignal *)addUserSignal:(NSDictionary *)userInfo {
return [RACSignal createSignal:^RACDisposable *(id
NSString *username = userInfo[@"username"];
NSString *email = userInfo[@"email"];
// 输入验证
if (!username || username.length == 0) {
NSError *error = [NSError errorWithDomain:@"ValidationError"
code:1001
userInfo:@{NSLocalizedDescriptionKey: @"Username is required"}];
[subscriber sendError:error];
return nil;
}
if (!email || email.length == 0) {
NSError *error = [NSError errorWithDomain:@"ValidationError"
code:1002
userInfo:@{NSLocalizedDescriptionKey: @"Email is required"}];
[subscriber sendError:error];
return nil;
}
User *newUser = [[User alloc] init];
newUser.username = username;
newUser.email = email;
[self->_userService createUser:newUser completion:^(User *user, NSError *error) {
if (error) {
[subscriber sendError:error];
} else {
[self->_mutableUsers addObject:user];
[subscriber sendNext:user];
[subscriber sendCompleted];
}
}];
return nil;
}];
}
- (RACSignal *)deleteUserSignal:(NSInteger)index {
return [RACSignal createSignal:^RACDisposable *(id
if (index < 0 || index >= self->_mutableUsers.count) {
NSError *error = [NSError errorWithDomain:@"ValidationError"
code:1003
userInfo:@{NSLocalizedDescriptionKey: @"Invalid user index"}];
[subscriber sendError:error];
return nil;
}
User *user = self->_mutableUsers[index];
[self->_userService deleteUserWithId:user.userId completion:^(BOOL success, NSError *error) {
if (error) {
[subscriber sendError:error];
} else if (success) {
[self->_mutableUsers removeObjectAtIndex:index];
[subscriber sendNext:@(index)];
[subscriber sendCompleted];
}
}];
return nil;
}];
}
// 属性访问器
- (NSArray
return [_mutableUsers copy];
}
- (BOOL)isLoading {
return self.loadUsersCommand.executing.boolValue ||
self.refreshUsersCommand.executing.boolValue ||
self.addUserCommand.executing.boolValue ||
self.deleteUserCommand.executing.boolValue;
}
- (User *)userAtIndex:(NSInteger)index {
if (index >= 0 && index < _mutableUsers.count) {
return _mutableUsers[index];
}
return nil;
}
- (NSInteger)numberOfUsers {
return _mutableUsers.count;
}
@end
2. View实现
// UserListMVVMViewController.h
@interface UserListMVVMViewController : UIViewController
@property (nonatomic, weak) IBOutlet UITableView *tableView;
@property (nonatomic, weak) IBOutlet UIActivityIndicatorView *loadingIndicator;
@property (nonatomic, strong) UserListViewModel *viewModel;
@end
// UserListMVVMViewController.m
@implementation UserListMVVMViewController
- (void)viewDidLoad {
[super viewDidLoad];
[self setupUI];
[self setupTableView];
[self setupViewModel];
[self bindViewModel];
}
- (void)setupUI {
self.title = @"Users (MVVM)";
UIBarButtonItem *refreshButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemRefresh
target:self
action:@selector(refreshUsers)];
UIBarButtonItem *addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd
target:self
action:@selector(addUser)];
self.navigationItem.rightBarButtonItems = @[addButton, refreshButton];
}
- (void)setupTableView {
self.tableView.delegate = self;
self.tableView.dataSource = self;
UINib *cellNib = [UINib nibWithNibName:@"UserTableViewCell" bundle:nil];
[self.tableView registerNib:cellNib forCellReuseIdentifier:@"UserTableViewCell"];
self.tableView.rowHeight = 80;
self.tableView.estimatedRowHeight = 80;
UIRefreshControl *refreshControl = [[UIRefreshControl alloc] init];
self.tableView.refreshControl = refreshControl;
}
- (void)setupViewModel {
UserService *userService = [UserService sharedService];
self.viewModel = [[UserListViewModel alloc] initWithUserService:userService];
}
- (void)bindViewModel {
// 绑定用户数据
[self.viewModel.usersSignal subscribeNext:^(NSArray
[self.tableView reloadData];
}];
// 绑定加载状态
[self.viewModel.loadingSignal subscribeNext:^(NSNumber *loading) {
if (loading.boolValue) {
[self.loadingIndicator startAnimating];
} else {
[self.loadingIndicator stopAnimating];
[self.tableView.refreshControl endRefreshing];
}
self.tableView.userInteractionEnabled = !loading.boolValue;
}];
// 绑定错误信息
[self.viewModel.errorSignal subscribeNext:^(NSError *error) {
[self showErrorAlert:error.localizedDescription];
}];
// 绑定刷新控件
self.tableView.refreshControl.rac_command = self.viewModel.refreshUsersCommand;
// 绑定添加用户结果
[self.viewModel.addUserCommand.executionSignals.switchToLatest subscribeNext:^(User *user) {
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:[self.viewModel numberOfUsers] - 1 inSection:0];
[self.tableView insertRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
}];
// 绑定删除用户结果
[self.viewModel.deleteUserCommand.executionSignals.switchToLatest subscribeNext:^(NSNumber *index) {
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:index.integerValue inSection:0];
[self.tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
}];
// 初始加载
[self.viewModel.loadUsersCommand execute:nil];
}
- (void)refreshUsers {
[self.viewModel.refreshUsersCommand execute:nil];
}
- (void)addUser {
UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"Add User"
message:@"Enter user information"
preferredStyle:UIAlertControllerStyleAlert];
[alert addTextFieldWithConfigurationHandler:^(UITextField *textField) {
textField.placeholder = @"Username";
}];
[alert addTextFieldWithConfigurationHandler:^(UITextField *textField) {
textField.placeholder = @"Email";
textField.keyboardType = UIKeyboardTypeEmailAddress;
}];
UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:@"Cancel"
style:UIAlertActionStyleCancel
handler:nil];
UIAlertAction *addAction = [UIAlertAction actionWithTitle:@"Add"
style:UIAlertActionStyleDefault
handler:^(UIAlertAction *action) {
NSString *username = alert.textFields[0].text;
NSString *email = alert.textFields[1].text;
NSDictionary *userInfo = @{
@"username": username ?: @"",
@"email": email ?: @""
};
[self.viewModel.addUserCommand execute:userInfo];
}];
[alert addAction:cancelAction];
[alert addAction:addAction];
[self presentViewController:alert animated:YES completion:nil];
}
- (void)showErrorAlert:(NSString *)message {
UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"Error"
message:message
preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction *okAction = [UIAlertAction actionWithTitle:@"OK"
style:UIAlertActionStyleDefault
handler:nil];
[alert addAction:okAction];
[self presentViewController:alert animated:YES completion:nil];
}
#pragma mark - UITableViewDataSource
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return [self.viewModel numberOfUsers];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UserTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"UserTableViewCell" forIndexPath:indexPath];
User *user = [self.viewModel userAtIndex:indexPath.row];
[cell configureWithUser:user];
return cell;
}
#pragma mark - UITableViewDelegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
[tableView deselectRowAtIndexPath:indexPath animated:YES];
User *user = [self.viewModel userAtIndex:indexPath.row];
NSLog(@"Selected user: %@", user.username);
}
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath {
return YES;
}
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
if (editingStyle == UITableViewCellEditingStyleDelete) {
UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"Delete User"
message:@"Are you sure you want to delete this user?"
preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:@"Cancel"
style:UIAlertActionStyleCancel
handler:nil];
UIAlertAction *deleteAction = [UIAlertAction actionWithTitle:@"Delete"
style:UIAlertActionStyleDestructive
handler:^(UIAlertAction *action) {
[self.viewModel.deleteUserCommand execute:@(indexPath.row)];
}];
[alert addAction:cancelAction];
[alert addAction:deleteAction];
[self presentViewController:alert animated:YES completion:nil];
}
}
@end
MVVM优缺点分析
优点：
数据绑定机制，减少样板代码
ViewModel易于测试
支持双向数据绑定
代码结构清晰，职责分离好
缺点：
学习成本高，需要理解响应式编程
调试相对困难
过度使用可能导致性能问题
需要额外的响应式编程框架支持
VIPER架构模式
VIPER基本原理
VIPER（View-Interactor-Presenter-Entity-Router）是一种更加细粒度的架构模式，将应用分为五个核心组件：
View：用户界面展示和用户交互
Interactor：业务逻辑处理
Presenter：格式化数据，处理View和Interactor之间的通信
Entity：数据模型
Router：导航逻辑处理
VIPER实现示例
1. Entity层
// UserEntity.h
@interface UserEntity : NSObject
@property (nonatomic, strong) NSString *userId;
@property (nonatomic, strong) NSString *username;
@property (nonatomic, strong) NSString *email;
@property (nonatomic, strong) NSDate *createdAt;
@property (nonatomic, assign) BOOL isActive;
- (instancetype)initWithUser:(User *)user;
- (User *)toUser;
@end
// UserEntity.m
@implementation UserEntity
- (instancetype)initWithUser:(User *)user {
self = [super init];
if (self) {
_userId = user.userId;
_username = user.username;
_email = user.email;
_createdAt = user.createdAt;
_isActive = user.isActive;
}
return self;
}
- (User *)toUser {
User *user = [[User alloc] init];
user.userId = self.userId;
user.username = self.username;
user.email = self.email;
user.createdAt = self.createdAt;
user.isActive = self.isActive;
return user;
}
@end
2. 协议定义
// UserListVIPERProtocols.h
// View协议
@protocol UserListViewProtocol
- (void)showUsers:(NSArray
- (void)showLoading:(BOOL)loading;
- (void)showError:(NSString *)errorMessage;
- (void)showUserAdded;
- (void)showUserDeleted;
@end
// Presenter协议
@protocol UserListPresenterProtocol
- (void)viewDidLoad;
- (void)refreshUsers;
- (void)addUserWithUsername:(NSString *)username email:(NSString *)email;
- (void)deleteUserAtIndex:(NSInteger)index;
- (void)selectUserAtIndex:(NSInteger)index;
- (UserEntity *)userAtIndex:(NSInteger)index;
- (NSInteger)numberOfUsers;
@end
// Interactor协议
@protocol UserListInteractorProtocol
- (void)fetchUsers;
- (void)createUserWithUsername:(NSString *)username email:(NSString *)email;
- (void)deleteUserAtIndex:(NSInteger)index;
@end
// Router协议
@protocol UserListRouterProtocol
- (void)navigateToUserDetail:(UserEntity *)user;
- (void)navigateToAddUser;
@end
// Interactor输出协议
@protocol UserListInteractorOutputProtocol
- (void)usersFetched:(NSArray
- (void)usersFetchFailed:(NSString *)errorMessage;
- (void)userCreated:(UserEntity *)user;
- (void)userCreationFailed:(NSString *)errorMessage;
- (void)userDeleted:(NSInteger)index;
- (void)userDeletionFailed:(NSString *)errorMessage;
@end
3. Interactor实现
// UserListInteractor.h
@interface UserListInteractor : NSObject
@property (nonatomic, weak) id
@property (nonatomic, strong) UserService *userService;
@property (nonatomic, strong) NSMutableArray
@end
// UserListInteractor.m
@implementation UserListInteractor
- (instancetype)init {
self = [super init];
if (self) {
_userService = [UserService sharedService];
_users = [NSMutableArray array];
}
return self;
}
- (void)fetchUsers {
[self.userService fetchUsersWithCompletion:^(NSArray
if (error) {
[self.output usersFetchFailed:error.localizedDescription];
} else {
[self.users removeAllObjects];
for (User *user in users) {
UserEntity *entity = [[UserEntity alloc] initWithUser:user];
[self.users addObject:entity];
}
[self.output usersFetched:[self.users copy]];
}
}];
}
- (void)createUserWithUsername:(NSString *)username email:(NSString *)email {
// 输入验证
if (!username || username.length == 0) {
[self.output userCreationFailed:@"Username is required"];
return;
}
if (!email || email.length == 0) {
[self.output userCreationFailed:@"Email is required"];
return;
}
User *newUser = [[User alloc] init];
newUser.username = username;
newUser.email = email;
[self.userService createUser:newUser completion:^(User *user, NSError *error) {
if (error) {
[self.output userCreationFailed:error.localizedDescription];
} else {
UserEntity *entity = [[UserEntity alloc] initWithUser:user];
[self.users addObject:entity];
[self.output userCreated:entity];
}
}];
}
- (void)deleteUserAtIndex:(NSInteger)index {
if (index < 0 || index >= self.users.count) {
[self.output userDeletionFailed:@"Invalid user index"];
return;
}
UserEntity *entity = self.users[index];
[self.userService deleteUserWithId:entity.userId completion:^(BOOL success, NSError *error) {
if (error) {
[self.output userDeletionFailed:error.localizedDescription];
} else if (success) {
[self.users removeObjectAtIndex:index];
[self.output userDeleted:index];
}
}];
}
@end
4. Presenter实现
// UserListPresenter.h
@interface UserListPresenter : NSObject
@property (nonatomic, weak) id
@property (nonatomic, strong) id
@property (nonatomic, strong) id
@property (nonatomic, strong) NSArray
@end
// UserListPresenter.m
@implementation UserListPresenter
- (instancetype)init {
self = [super init];
if (self) {
_users = @[];
}
return self;
}
#pragma mark - UserListPresenterProtocol
- (void)viewDidLoad {
[self.view showLoading:YES];
[self.interactor fetchUsers];
}
- (void)refreshUsers {
[self.interactor fetchUsers];
}
- (void)addUserWithUsername:(NSString *)username email:(NSString *)email {
[self.view showLoading:YES];
[self.interactor createUserWithUsername:username email:email];
}
- (void)deleteUserAtIndex:(NSInteger)index {
[self.view showLoading:YES];
[self.interactor deleteUserAtIndex:index];
}
- (void)selectUserAtIndex:(NSInteger)index {
if (index >= 0 && index < self.users.count) {
UserEntity *user = self.users[index];
[self.router navigateToUserDetail:user];
}
}
- (UserEntity *)userAtIndex:(NSInteger)index {
if (index >= 0 && index < self.users.count) {
return self.users[index];
}
return nil;
}
- (NSInteger)numberOfUsers {
return self.users.count;
}
#pragma mark - UserListInteractorOutputProtocol
- (void)usersFetched:(NSArray
self.users = users;
[self.view showLoading:NO];
[self.view showUsers:users];
}
- (void)usersFetchFailed:(NSString *)errorMessage {
[self.view showLoading:NO];
[self.view showError:errorMessage];
}
- (void)userCreated:(UserEntity *)user {
self.users = [self.users arrayByAddingObject:user];
[self.view showLoading:NO];
[self.view showUserAdded];
}
- (void)userCreationFailed:(NSString *)errorMessage {
[self.view showLoading:NO];
[self.view showError:errorMessage];
}
- (void)userDeleted:(NSInteger)index {
NSMutableArray *mutableUsers = [self.users mutableCopy];
[mutableUsers removeObjectAtIndex:index];
self.users = [mutableUsers copy];
[self.view showLoading:NO];
[self.view showUserDeleted];
}
- (void)userDeletionFailed:(NSString *)errorMessage {
[self.view showLoading:NO];
[self.view showError:errorMessage];
}
@end