- (UICollectionViewFlowLayout *)flowlayout
{
    if (!_flowlayout) {
        _flowlayout = [[UICollectionViewFlowLayout alloc] init];
        _flowlayout.minimumInteritemSpacing = 0;
        _flowlayout.minimumLineSpacing = 0;
        _flowlayout.sectionInset = UIEdgeInsetsMake(0, 0, 0, 0);
        _flowlayout.delegate = self;
   }
   return _flowlayout;
}