開篇
MVC Model-View-Controller是一個用來組織代碼的權威范式。Apple甚至是這么說的。在MVC下，所有的對象被歸類為一個model，一個view，或一個controller。Model持有數據，View顯示與用戶交互的界面，而View Controller調解Model和View之間的交互。
MVVM MVVM的出現主要是為了解決在開發過程中Controller越來越龐大的問題，變得難以維護，所以MVVM把數據加工的任務從Controller中解放了出來，使得Controller只需要專注于數據調配的工作，ViewModel則去負責數據加工并通過通知機制讓View響應ViewModel的改變。

效果圖

9a16f55c773f2312664c0818e2d5864b.png

源碼分析
1.Model模塊

首先是model層的代碼，創建MovieModel類，繼承自NSObject。設置幾個屬性movieName、year、imageUrl、detailUrl（用于跳轉）

#import <Foundation>

@interface MovieModel : NSObject
@property (strong, nonatomic) NSString *movieName;
@property (strong, nonatomic) NSString *year;
@property (strong, nonatomic) NSURL *imageUrl;
@property (strong, nonatomic) NSString *detailUrl;
@end

ViewController模塊

ViewController里面是用來從MovieViewModel中獲取數據信息然后展示到UITableView的cell上面，和點擊單元格的頁面跳轉

#import "HomeViewController.h"
#import "MovieViewModel.h"
#import "MovieCell.h"
@interface HomeViewController ()<UITableViewDataSource>

@property (nonatomic,strong) NSArray *modelArray;
@end

@implementation HomeViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.title = @"電影首頁";
    self.view.backgroundColor = [UIColor redColor];

    UITableView *tableView = [[UITableView alloc] initWithFrame:self.view.bounds style:UITableViewStylePlain];
    tableView.dataSource = self;
    tableView.delegate = self;
    tableView.rowHeight = 80;
    [self.view addSubview:tableView];
    [tableView registerClass:[MovieCell class] forCellReuseIdentifier:@"MovieCell"];

    //初始化MovieViewModel，設置成功（returnBlock）和失敗的回調（errorBlock），getMovieData去請求數據，請求數據成功即回調上一步設置的returnBlock，請求失敗則回調errorBlock
    MovieViewModel *viewModel = [[MovieViewModel alloc] init];
    viewModel.returnBlock = ^(id returnValue){

        _modelArray = returnValue;
        [tableView reloadData];
    };
    viewModel.errorBlock = ^(id errorCode){

        NSLog(@"%@",errorCode);
    };

    [viewModel getMovieData];

}

#pragma mark - UITableViewDataSource
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
    return _modelArray.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
    MovieCell *cell = [tableView dequeueReusableCellWithIdentifier:@"MovieCell"];
    cell.model = _modelArray[indexPath.row];
    return cell;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
    MovieViewModel *movieViewModel = [[MovieViewModel alloc] init];
    [movieViewModel movieDetailWithPublicModel:_modelArray[indexPath.row] WithViewController:self];
}

@end

View模塊

view這里跟MVC中子類化UITableViewCell一樣，將model數據傳進來，復寫setModel方法給視圖傳遞數據

#import "MovieModel.h"
@interface MovieCell : UITableViewCell
@property (nonatomic,strong) MovieModel *model;
@end

#import "MovieCell.h"
#import "UIImageView+AFNetworking.h"
@interface MovieCell()
@property (nonatomic,strong) UILabel *nameLabel;
@property (nonatomic,strong) UILabel *yearLabel;
@property (nonatomic,strong) UIImageView *imgView;
@end
@implementation MovieCell

- (instancetype)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier{
    self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
    if (self) {
        _imgView = [[UIImageView alloc] initWithFrame:CGRectMake(15, 10, 40, 60)];
        [self.contentView addSubview:_imgView];

        _nameLabel = [[UILabel alloc] initWithFrame:CGRectMake(70, 10, 200, 20)];
        [self.contentView addSubview:_nameLabel];

        _yearLabel = [[UILabel alloc] initWithFrame:CGRectMake(70, 50, 100, 20)];
        _yearLabel.textColor = [UIColor lightGrayColor];
        _yearLabel.font = [UIFont systemFontOfSize:14];
        [self.contentView addSubview:_yearLabel];
    }
    return self;
}

- (void)setModel:(MovieModel *)model{
    _model = model;
    _nameLabel.text = _model.movieName;
    _yearLabel.text = _model.year;
    [_imgView setImageWithURL:_model.imageUrl];
}

@end

ViewModel模塊

ViewModel是最重要的模塊： 1.這里面進行了數據的網絡請求，并將數據轉換成model放在一個數組中，調用_returnBlock將model數組傳遞給viewController進行數據源的處理 2.將頁面跳轉的邏輯放在ViewModel中，點擊單元格進行頁面跳轉的時候直接在- (void)tableView:(UITableView )tableView didSelectRowAtIndexPath:(NSIndexPath )indexPath中調用MovieViewModel的該方法即可

#import <Foundation>
#import "MovieModel.h"
#import <UIKit>

typedef void (^ReturnValueBlock) (id returnValue);
typedef void (^ErrorCodeBlock) (id errorCode);

@interface MovieViewModel : NSObject
@property (nonatomic,copy) ReturnValueBlock returnBlock;
@property (nonatomic,copy) ErrorCodeBlock errorBlock;

//獲取電影數據
- (void)getMovieData;
//跳轉到電影詳情頁
- (void)movieDetailWithPublicModel: (MovieModel *)movieModel WithViewController: (UIViewController *)superController;
@end

#import "MovieViewModel.h"
#import "NetworkService.h"
#import "MovieModel.h"
#import "MovieViewController.h"

@implementation MovieViewModel

- (void)getMovieData{
    [NetworkService requestWithURL:@"/v2/movie/coming_soon" params:nil success:^(id result) {
        NSLog(@"%@",result);

        NSArray *subjects = result[@"subjects"];
        NSMutableArray *modelArr = [NSMutableArray arrayWithCapacity:subjects.count];
        for (NSDictionary *subject in subjects) {
            MovieModel *model = [[MovieModel alloc] init];
            model.movieName = subject[@"title"];
            model.year = subject[@"year"];
            NSString *urlStr = subject[@"images"][@"medium"];
            model.imageUrl = [NSURL URLWithString:urlStr];
            model.detailUrl = subject[@"alt"];
            [modelArr addObject:model];
        }
        _returnBlock(modelArr);

    } failure:^(NSError *error) {
         NSLog(@"%@",error);
        _errorBlock(error);
    }];
}

- (void)movieDetailWithPublicModel: (MovieModel *)movieModel WithViewController: (UIViewController *)superController{
    MovieViewController *movieVC = [[MovieViewController alloc] init];
    movieVC.url = movieModel.detailUrl;
    [superController.navigationController pushViewController:movieVC animated:YES];
}
@end