IOS开发-项目实战-点赞功能的实现

            -(void)TableViewForCell:(News_TableViewCell *)cell andbutton:(UIButton *)button{
     
//    获得点击了那一行
    NSIndexPath *indexPath = [Mytabview indexPathForCell:cell];
    NSString *className = @"dian_zan";
    
    Newmodel *news = _allmodelNews[indexPath.row];
    BmobObject *data = [[BmobObject alloc] initWithClassName:className];
//    获得当前用户
    BmobUser *user = [BmobUser getCurrentUser];
    
    BmobQuery *query = [BmobQuery queryWithClassName:className];
//    两个判断条件，用户的ID和此条新闻的ID作判断
    [query whereKey:@"newsID" equalTo:news.ID];
    [query whereKey:@"userID" equalTo:user.objectId];

    [query findObjectsInBackgroundWithBlock:^(NSArray *array, NSError *error)  {
        NSLog(@"error == %@",error);
//        用户点击过if (array.count!=0) {
//            取到已经点赞的那一行
            BmobObject *zanObj = array[0];
//            用户取消点赞或者点赞
            BOOL zann = [[zanObj objectForKey:@"dianzan"] boolValue]==NO?YES:NO;
            
            BmobObject *data = [BmobObject objectWithoutDatatWithClassName:className objectId:zanObj.objectId];
//            最终结果上传云端
            [data setObject:@(zann) forKey:@"dianzan"];
            [data updateInBackgroundWithResultBlock:^(BOOL isSuccessful, NSError *error) {
                if (!error) {
                           }
            }];
            
        }else{
//        用户没有点击过的话，就保存用户点赞
            [data setObject:user.objectId forKey:@"userID"];
            [data setObject:news.ID forKey:@"newsID"];
            [data setObject:@(YES) forKey:@"dianzan"];
//            [data setObject:@(indexPath.row) forKey:@"row"];
            [data saveInBackgroundWithResultBlock:^(BOOL isSuccessful, NSError *error) {
                NSLog(@"tijiao == %@",error);
                if (!error) {
                         }
            }];
        }
        
      }];
    
}
        

            
                 1
                #pragma mark----------------网络数据下载-----------------------
 2 -(NSArray *)allmodelNew{
 3//    每次调用该方法初始化点赞数组，保证每条新闻的数据互不影响。 4     zan = [NSMutableArray array];//由于数据下载是异步下载，所以点赞和其他数据各用一个可变数据存放数据 5     NSString *className = @"CampusNews";
 6     NSMutableArray *all = [NSMutableArray array];
 7     BmobQuery *quer = [BmobQuery queryWithClassName:className];
 8     [quer orderByDescending:@"updatedAt"];
 9     quer.limit = 3;
10     [quer findObjectsInBackgroundWithBlock:^(NSArray *array, NSError *error) {
1112for (BmobObject *data in array) {
13//            用一个Newmodel模型来装载数据14             Newmodel *info    = [[Newmodel alloc] init];
15if ([data objectForKey:@"name"]) {
16                 info.name    = [data objectForKey:@"name"];
17            }
18if ([data objectForKey:@"text"]) {
19                 info.text  = [data objectForKey:@"text"];
20            }
21             info.time   = [dateformatter stringFromDate:data.updatedAt];
22             info.ID = data.objectId;
23#pragma mark---------------点赞计算--------------------------
24//            查找点赞个数25             BmobQuery *query = [BmobQuery queryWithClassName:@"dian_zan"];
26//            查找该账号的所有点赞数据（并且全部是YES的数据）27             [query whereKey:@"newsID" equalTo:data.objectId];
28             [query whereKey:@"dianzan" equalTo:@(YES)];
29             [query findObjectsInBackgroundWithBlock:^(NSArray *array, NSError *error) {
30//                可变数组zan31                [zan addObject:@(array.count)];
3233            }];
3435            [all addObject:info];
36        }
37         _allmodelNews = all;
38if (_allmodelNews.count == _allmodelNews.count) {
39            [Mytabview.footer endRefreshing];
40        }
4142        [self performSelectorOnMainThread:@selector(upDateUI) withObject:nil waitUntilDone:YES];
43           }];
44return _allmodelNews;
45 }