MVVM的项目学习和笔记

今天在学习一个用MVVM模式写的项目,掌握一下对MVVM的理解和记的一些笔记.

下面是自己学习的项目链接:

http://www.code4app.com/ios/一个MVVM架构的iOS工程/695f5862-f1d5-11e5-af82-00163e0606f4

1.

一个MVVM架构的iOS工程 :

Model层是少不了的了，我们得有东西充当DTO(数据传输对象)，当然，用字典也是可以的，Model层是比较薄的一层；

ViewModel层，就是View和Model层的粘合剂，他是一个放置用户输入验证逻辑，视图显示逻辑，发起网络请求和其他各种各样的代码的极好的地方。说白了，就是把原来ViewController层的业务逻辑和页面逻辑等剥离出来放到ViewModel层。

View层，就是ViewController层，他的任务就是从ViewModel层获取数据，然后显示。

2.

1>

自定义Model类:

@interface PublicModel : NSObject

@property (strong, nonatomic) NSString *userId;

@property (strong, nonatomic) NSString *weiboId;

@property (strong, nonatomic) NSString *userName;

@property (strong, nonatomic) NSURL *imageUrl;

@property (strong, nonatomic) NSString *date;

@property (strong, nonatomic) NSString *text;

@end

ViewModel部分:

1>自定义Model1类,接收数据:

 #pragma 接收穿过来的block
 -(void) setBlockWithReturnBlock: (ReturnValueBlock) returnBlock
                  WithErrorBlock: (ErrorCodeBlock) errorBlock
                WithFailureBlock: (FailureBlock) failureBlock
 {
     _returnBlock = returnBlock;
     _errorBlock = errorBlock;
     _failureBlock = failureBlock;
 }

2>再定义Model2类,继承自Model1类:

进行网络请求,对请求下来的数据进行数据处理,处理跳转到详情页面.

 @implementation PublicWeiboViewModel

 //获取公共微博
 -(void) fetchPublicWeiBo
 {
     NSDictionary *parameter = @{TOKEN: ACCESSTOKEN,
                                 COUNT: @""
                                 };
     [NetRequestClass NetRequestGETWithRequestURL:REQUESTPUBLICURL WithParameter:parameter WithReturnValeuBlock:^(id returnValue) {

         DDLog(@"%@", returnValue);
         [self fetchValueSuccessWithDic:returnValue];

     } WithErrorCodeBlock:^(id errorCode) {
         DDLog(@"%@", errorCode);
         [self errorCodeWithDic:errorCode];

     } WithFailureBlock:^{
         [self netFailure];
         DDLog(@"网络异常");

     }];

 }

 #pragma 获取到正确的数据，对正确的数据进行处理
 -(void)fetchValueSuccessWithDic: (NSDictionary *) returnValue
 {
     //对从后台获取的数据进行处理，然后传给ViewController层进行显示

     NSArray *statuses = returnValue[STATUSES];
     NSMutableArray *publicModelArray = [[NSMutableArray alloc] initWithCapacity:statuses.count];

     for (int i = ; i < statuses.count; i ++) {
         PublicModel *publicModel = [[PublicModel alloc] init];

         //设置时间
         NSDateFormatter *iosDateFormater=[[NSDateFormatter alloc]init];
         iosDateFormater.dateFormat=@"EEE MMM d HH:mm:ss Z yyyy";

         //必须设置，否则无法解析
         iosDateFormater.locale=[[NSLocale alloc]initWithLocaleIdentifier:@"en_US"];
         NSDate *date=[iosDateFormater dateFromString:statuses[i][CREATETIME]];

         //目的格式
         NSDateFormatter *resultFormatter=[[NSDateFormatter alloc]init];
         [resultFormatter setDateFormat:@"MM月dd日 HH:mm"];

         publicModel.date = [resultFormatter stringFromDate:date];
         publicModel.userName = statuses[i][USER][USERNAME];
         publicModel.text = statuses[i][WEIBOTEXT];
         publicModel.imageUrl = [NSURL URLWithString:statuses[i][USER][HEADIMAGEURL]];
         publicModel.userId = statuses[i][USER][UID];
         publicModel.weiboId = statuses[i][WEIBOID];

         [publicModelArray addObject:publicModel];

     }

     self.returnBlock(publicModelArray);
 }

 #pragma 对ErrorCode进行处理
 -(void) errorCodeWithDic: (NSDictionary *) errorDic
 {
     self.errorBlock(errorDic);
 }

 #pragma 对网路异常进行处理
 -(void) netFailure
 {
     self.failureBlock();
 }

 #pragma 跳转到详情页面，如需网路请求的，可在此方法中添加相应的网络请求
 -(void) weiboDetailWithPublicModel: (PublicModel *) publicModel WithViewController:(UIViewController *)superController
 {
     DDLog(@"%@,%@,%@",publicModel.userId,publicModel.weiboId,publicModel.text);
     UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:[NSBundle mainBundle]];
     PublicDetailViewController *detailController = [storyboard instantiateViewControllerWithIdentifier:@"PublicDetailViewController"];
     detailController.publicModel = publicModel;
     [superController.navigationController pushViewController:detailController animated:YES];

 }

 @end

3.Controller部分:

接收model数据,定义表视图,实现其协议方法.

 @implementation PublicTableViewController

 - (void)viewDidLoad {
     [super viewDidLoad];

     // 接收数据

     PublicWeiboViewModel *publicViewModel = [[PublicWeiboViewModel alloc] init];

     [publicViewModel setBlockWithReturnBlock:^(id returnValue) {

         [SVProgressHUD dismiss];
         _publicModelArray = returnValue;
         [self.tableView reloadData];
         DDLog(@"%@",_publicModelArray);

     } WithErrorBlock:^(id errorCode) {

         [SVProgressHUD dismiss];

     } WithFailureBlock:^{

         [SVProgressHUD dismiss];

     }];

     [publicViewModel fetchPublicWeiBo];

     [SVProgressHUD showWithStatus:@"正在获取用户信息……" maskType:SVProgressHUDMaskTypeBlack];

 }

 - (void)didReceiveMemoryWarning {
     [super didReceiveMemoryWarning];
     // Dispose of any resources that can be recreated.
 }

 #pragma mark - Table view data source

 - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
     return ;
 }

 - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {

     return _publicModelArray.count;
 }

 - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
     PublicCell *cell = [tableView dequeueReusableCellWithIdentifier:@"PublicCell" forIndexPath:indexPath];

     [cell setValueWithDic:_publicModelArray[indexPath.row]];

     return cell;
 }

 -(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
 {
     PublicWeiboViewModel *publicViewModel = [[PublicWeiboViewModel alloc] init];
     [publicViewModel weiboDetailWithPublicModel:_publicModelArray[indexPath.row] WithViewController:self];
 }

总结:

1.其实际上MVVM和MVC设计模式大体上是一样的,只是把MVC在C中请求网络和处理数据信息的部分子类了在ViewModel中实现,减轻了C的负担和代码量;

2.Model的存储数据还是不变;