ios 只刷新某一行或某一组cell

//一个section刷新

NSIndexSet *indexSet=[[NSIndexSet alloc]initWithIndex:2];

[tableview reloadSections:indexSet withRowAnimation:UITableViewRowAnimationAutomatic];

//一个cell刷新

NSIndexPath *indexPath=[NSIndexPath indexPathForRow:3 inSection:0];

[tableView reloadRowsAtIndexPaths:[NSArray arrayWithObjects:indexPath,nil] withRowAnimation:UITableViewRowAnimationNone];