UIRefreshControl

　　//1.初始化
    UIRefreshControl *control = [[UIRefreshControl alloc] init];
    //指定给tableViewController
    self.refreshControl = control;
    //添加tagter action
    [control addTarget:self action:@selector(loadNew:) forControlEvents:UIControlEventValueChanged];
    //设置属性字符串标题
    NSAttributedString *title = [[NSAttributedString alloc] initWithString:@"下拉刷新" attributes:@{NSFontAttributeName : [UIFont systemFontOfSize:15], NSForegroundColorAttributeName : [UIColor orangeColor]}];
    control.attributedTitle = title;

            //刷新UI
            [self.tableView reloadData];

   //刷新玩数据之后要结束刷新
   [self.refreshControl endRefreshing];