iOS开发之 collectionView 刷新单个重影问题

在做项目使用collectionView的时候遇到了只需刷新某个cell的情况。按照常规思路去刷新：

  NSIndexPath *topHeaderViewIndexpath = [[self.tableView indexPathsForVisibleRows] firstObject];
        NSIndexPath *moveToIndexpath = [NSIndexPath indexPathForRow:topHeaderViewIndexpath.section inSection:0];
       if (![moveToIndexpath isEqual:self.selectIndex] && self.isclickCollection != YES) {
           NSIndexPath *lastIndex = self.selectIndex;
           self.selectIndex = moveToIndexpath;
               [self.topCollectionView reloadItemsAtIndexPaths:@[lastIndex,moveToIndexpath]];
               [self.topCollectionView selectItemAtIndexPath:moveToIndexpath animated:YES scrollPosition:UICollectionViewScrollPositionLeft];

  
       }

然后发现刷新的时候会有重影，后来改成如下代码成功解决重影问题：

    NSIndexPath *topHeaderViewIndexpath = [[self.tableView indexPathsForVisibleRows] firstObject];
        NSIndexPath *moveToIndexpath = [NSIndexPath indexPathForRow:topHeaderViewIndexpath.section inSection:0];
       if (![moveToIndexpath isEqual:self.selectIndex] && self.isclickCollection != YES) {
           NSIndexPath *lastIndex = self.selectIndex;
           self.selectIndex = moveToIndexpath;

          //解决重影重点
           [UIView performWithoutAnimation:^{
               [self.topCollectionView reloadItemsAtIndexPaths:@[lastIndex,moveToIndexpath]];
               [self.topCollectionView selectItemAtIndexPath:moveToIndexpath animated:YES scrollPosition:UICollectionViewScrollPositionLeft];
           }];

  
       }