开篇
MVC Model-View-Controller是一个用来组织代码的权威范式。Apple甚至是这么说的。在MVC下,所有的对象被归类为一个model,一个view,或一个controller。Model持有数据,View显示与用户交互的界面,而View Controller调解Model和View之间的交互。 MVVM MVVM的出现主要是为了解决在开发过程中Controller越来越庞大的问题,变得难以维护,所以MVVM把数据加工的任务从Controller中解放了出来,使得Controller只需要专注于数据调配的工作,ViewModel则去负责数据加工并通过通知机制让View响应ViewModel的改变。
效果图
源码分析
1.Model模块
首先是model层的代码,创建MovieModel类,继承自NSObject。设置几个属性movieName、year、imageUrl、detailUrl(用于跳转)
#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模块
ViewController里面是用来从MovieViewModel中获取数据信息然后展示到UITableView的cell上面,和点击单元格的页面跳转
#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 = @"电影首页"; 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,设置成功(returnBlock)和失败的回调(errorBlock),getMovieData去请求数据,请求数据成功即回调上一步设置的returnBlock,请求失败则回调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模块
view这里跟MVC中子类化UITableViewCell一样,将model数据传进来,复写setModel方法给视图传递数据
#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模块
ViewModel是最重要的模块: 1.这里面进行了数据的网络请求,并将数据转换成model放在一个数组中,调用_returnBlock将model数组传递给viewController进行数据源的处理 2.将页面跳转的逻辑放在ViewModel中,点击单元格进行页面跳转的时候直接在- (void)tableView:(UITableView )tableView didSelectRowAtIndexPath:(NSIndexPath )indexPath中调用MovieViewModel的该方法即可
#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; //获取电影数据 - (void)getMovieData; //跳转到电影详情页 - (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