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: @"100"
                                };
    [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 = 0; 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 1;
}

- (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;