廢話不多說(shuō)纯丸，直接上代碼
我們的model：User，可以看出來(lái)和MVC里沒(méi)有區(qū)別

#import <Foundation/Foundation.h>

@interface User : NSObject

+ (instancetype)userWithFirstName:(NSString *)firstName lastName:(NSString *)lastName email:(NSString *)email age:(NSInteger )age;

@property (copy, nonatomic) NSString *firstName;
@property (copy, nonatomic) NSString *lastName;
@property (copy, nonatomic) NSString *email;
@property (nonatomic) NSInteger age;


@end


#import "User.h"

@implementation User
+ (instancetype)userWithFirstName:(NSString *)firstName lastName:(NSString *)lastName email:(NSString *)email age:(NSInteger )age {
    return [[self alloc] initWithFirstName:firstName lastName:lastName email:email age:age];
}
- (instancetype)initWithFirstName:(NSString *)firstName lastName:(NSString *)lastName email:(NSString *)email age:(NSInteger )age
{
    self = [super init];
    if (self) {
        _firstName = firstName;
        _lastName = lastName;
        _email = email;
        _age = age;
    }
    return self;
}
@end

這里我們?cè)黾恿艘粋€(gè)服務(wù)器層构捡，用于取網(wǎng)絡(luò)數(shù)據(jù)模擬UserService液南，看到頭文件我突然想起了之前在一家公司寫代碼，就是這樣的效果勾徽，你完全不知道是請(qǐng)求的網(wǎng)絡(luò)還是本地?cái)?shù)據(jù)滑凉，你也完全不用創(chuàng)建User模型 ，你需要做的只是調(diào)用一個(gè)類的一個(gè)方法喘帚，你就能得到一個(gè)對(duì)象畅姊，或者一堆對(duì)象。這就是站在UI層寫代碼的便捷之處吹由。

#import <Foundation/Foundation.h>
@class User;

@interface UserService : NSObject

- (void)getUsers:(void (^)(NSArray<User *> *users))usersBlock;
@end


#import "UserService.h"
#import "User.h"
@implementation UserService

- (void)getUsers:(void (^)(NSArray<User *> *users))usersBlock {
    
    NSInteger userCount = 3;
    NSMutableArray<User *> *users = [NSMutableArray arrayWithCapacity:userCount];
    for (NSInteger i = 0; i < userCount; ++i) {
        NSString *idxStr = [NSString stringWithFormat:@"%zd", i];
        User *user =
        [User userWithFirstName:idxStr lastName:idxStr email:idxStr age:i];
        [users addObject:user];
    }
    double delay = 2;
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delay * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        
        if (usersBlock) {
            usersBlock(users);
        }
    });
}
@end

然后我們會(huì)有一個(gè)展示層UserPresenter
我們定義了一個(gè)類UserViewData若未，類似MVVM里經(jīng)過(guò)最原始的model處理過(guò)后得到的viewModel一樣，當(dāng)然MVVM里好像是把網(wǎng)絡(luò)層放到了viewModel里倾鲫，這里MVP有個(gè)專門的服務(wù)類來(lái)做這類事情 粗合。這個(gè)UserViewData是userView能直接用的模型
我們還定義了一個(gè)協(xié)議UserViewDelegate，用于處理乌昔，加載數(shù)據(jù)和完成加載數(shù)據(jù)和設(shè)置數(shù)據(jù)源和為空時(shí)的處理隙疚。
然后我們的展示層UserPresenter，要展示當(dāng)然是要有數(shù)據(jù)磕道，所以 UserPresenter的初始化方法依賴于UserService供屉，當(dāng)然有了數(shù)據(jù)之后，可以展示與不展示溺蕉，這里有個(gè)userViewDelegate屬性伶丐。還有個(gè)getUsers方法，在調(diào)用這個(gè)方法里就會(huì)調(diào)用
userViewDelegate里的加載完成加載設(shè)置數(shù)據(jù)和空數(shù)據(jù)之類的操作疯特。相對(duì)于MVC來(lái)說(shuō)的確代碼量上去了哗魂。項(xiàng)目小可能感受不到好處，項(xiàng)目大了漓雅，業(yè)務(wù)復(fù)雜了可能就有體會(huì)了啡彬，當(dāng)你看到別人寫2500行的控制器時(shí)可能就會(huì)思考其他模式來(lái)進(jìn)行優(yōu)化了羹与，其實(shí)模式是可以共存在一個(gè)項(xiàng)目里，針對(duì)不同的模塊選用不同的模式庶灿。
簡(jiǎn)單的MVC纵搁，復(fù)雜的后期需要擴(kuò)展的可用MVP、MVVM等往踢。之前好像聽(tīng)一個(gè)朋友說(shuō)VIP模式腾誉，真是吊啊，什么模式都有峻呕，只怪我們太年少利职，不努力學(xué)習(xí)。

import <Foundation/Foundation.h>
@class UserService;

@interface UserViewData: NSObject

@property (copy, nonatomic) NSString *name;
@property (copy, nonatomic) NSString *age;
+ (instancetype)userViewDataWithName:(NSString *)name age:(NSString *)age;
@end

@protocol UserViewDelegate
- (void)startLoading;
- (void)finishLoading;
- (void)setUsers:(NSArray<UserViewData *> *)userViewDatas;
- (void)setEmptyUsers;
@end

@interface UserPresenter : NSObject

+ (instancetype)userPresenterWithUserService:(UserService *)userService;
@property(nonatomic, weak)  id<UserViewDelegate> userViewDelegate;
- (void)getUsers;

@end



#import "UserPresenter.h"
#import "UserService.h"
#import "User.h"
@implementation UserViewData
+ (instancetype)userViewDataWithName:(NSString *)name age:(NSString *)age {
    return [[self alloc] initWithName:name age:age];
}
- (instancetype)initWithName:(NSString *)name age:(NSString *)age {
    
    
    self = [super init];
    if (self) {
        _name = name;
        _age = age;
    }
    return self;
}
@end

@interface UserPresenter()

@property(nonatomic, strong)  UserService *userService;

@end
@implementation UserPresenter
+ (instancetype)userPresenterWithUserService:(UserService *)userService
{
    return [[self alloc] initWithUserService:userService];
}


- (instancetype)initWithUserService:(UserService *)userService
{
    self = [super init];
    if (self) {
        _userService = userService;
    }
    return self;
}
-(void)attachView:(id<UserViewDelegate>)userView {
    _userViewDelegate = userView;
}
-(void)detachView {
    _userViewDelegate = nil;
}
- (void)getUsers {
    [self.userViewDelegate startLoading];
    
    __weak __typeof(self)weakSelf = self;
    [self.userService getUsers:^(NSArray *users) {
        
        [weakSelf.userViewDelegate finishLoading];
        if (users.count == 0) {
            [self.userViewDelegate setEmptyUsers];
        } else {
            NSMutableArray<UserViewData *> *userViewDatas = [NSMutableArray arrayWithCapacity:3];
            for (User *user in users) {
                NSString *ageStr = [NSString stringWithFormat:@"%zd", user.age];
                UserViewData *userViewData = [UserViewData userViewDataWithName:user.firstName age:ageStr];
                [userViewDatas addObject:userViewData];
            }
            
            [self.userViewDelegate setUsers:userViewDatas];
        }
    }];
}
@end

最后控制器里就是一些view的處理及代理實(shí)現(xiàn)瘦癌，拼裝一些類猪贪。

image.png

#import "ViewController.h"
#import "UserPresenter.h"
#import "UserService.h"
@interface ViewController ()<UITableViewDataSource, UserViewDelegate>
@property (weak, nonatomic) IBOutlet UIView *emptyView;
@property (weak, nonatomic) IBOutlet UITableView *tableView;
@property (weak, nonatomic) IBOutlet UIActivityIndicatorView *indicator;


@property(nonatomic, strong) UserPresenter *userPresenter;
@property(nonatomic, strong) NSArray<UserViewData *> *userViewDatas;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    self.tableView.dataSource = self;
    self.indicator.hidesWhenStopped = YES;
    self.userPresenter = [UserPresenter userPresenterWithUserService:[UserService new]];
    self.userPresenter.userViewDelegate = self;
    [self.userPresenter getUsers];
}

#pragma mark - UserViewDelegate
-(void)startLoading {
    [self.indicator startAnimating];
}
-(void)finishLoading {
    [self.indicator stopAnimating];
}
-(void)setUsers:(NSArray<UserViewData *> *)userViewDatas {
    self.userViewDatas = userViewDatas;
    self.tableView.hidden = NO;
    self.emptyView.hidden = YES;
    [self.tableView reloadData];
}
-(void)setEmptyUsers {
    self.tableView.hidden = YES;
    self.emptyView.hidden = NO;
}
#pragma mark - UITableViewDataSource
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return self.userViewDatas.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    
    NSString *cellIDStr = @"user";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier: cellIDStr];
    if (cell == nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIDStr];
    }
    
    UserViewData *userViewData = self.userViewDatas[indexPath.row];
    cell.textLabel.text = userViewData.name;
    cell.detailTextLabel.text = userViewData.age;
    
    return cell;
}
@end