iOS 刷新tableView中某一个cell或者某一个sect

//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];