ios9.0以后 uicollectionview 拖拽 怎么固定某个cell无法移动,别的cell拖动时也无法挤压这个cell?

ios9.0以后 uicollectionview 拖拽 怎么固定某个cell无法移动,别的cell拖动时也无法挤压这个cell?用iOS9.0以后的方法,有人知道吗?

- (NSIndexPath *)collectionView:(UICollectionView *)collectionView targetIndexPathForMoveFromItemAtIndexPath:(NSIndexPath *)originalIndexPath toProposedIndexPath:(NSIndexPath *)proposedIndexPath{
    
    if([self.adapter checkEditableOfIndexPath:proposedIndexPath]){
        return proposedIndexPath;
    }
    return originalIndexPath;
}

UICollectionView代理方法，判断proposedIndexPath是否可编辑，返回合适第indexpath

    case UIGestureRecognizerStateChanged:
    { // 手势改变
        // iOS9方法 移动过程中随时更新cell位置

        NSIndexPath *indexPath = [self.collectionView indexPathForItemAtPoint:[longPress locationInView:self.collectionView]];
        if (!indexPath) {
            break;
        }
        if (indexPath.row == 需要固定的row) {
            return;
        }

        [self.collectionView updateInteractiveMovementTargetPosition:[longPress locationInView:self.collectionView]];
    }
        break;