UICollectionView 刷新指定单元格或刷指定分区

        BOOL animationsEnabled = [UIView areAnimationsEnabled];
        [UIView setAnimationsEnabled:NO];
        NSIndexPath *indexPath=[NSIndexPath indexPathForRow:2 inSection:0];
        [self.collectionView reloadItemsAtIndexPaths:[NSArray arrayWithObjects:indexPath,nil]];
        [UIView setAnimationsEnabled:animationsEnabled];

                    if(isCommonUnitEmptyArray(self.model.data))
                    {
                        [self.collectionView reloadData];
                    }
                    else{
                        NSIndexSet *indexSet=[[NSIndexSet alloc]initWithIndex:1];
                        //为了避免重新加载时出现不需要的动画（又名“闪烁”)
                        BOOL animationsEnabled = [UIView areAnimationsEnabled];
                        [UIView setAnimationsEnabled:NO];
                        [self.collectionView reloadSections:indexSet];
            //            [self.collectionView reloadSections:indexSet withRowAnimation:UITableViewRowAnimationAutomatic];
                        [UIView setAnimationsEnabled:animationsEnabled];
                    }