[self.cvCollection reloadData];
[self.cvCollection.collectionViewLayout invalidateLayout];
//部分系统上 reload [UICollectionViewData validateLayoutInRect:] crash
self.flLayout.estimatedItemSize = CGSizeMake(50, 50);
if (isIOS8) {
self.cvCollection.contentInset = UIEdgeInsetsMake(0, 15, 0, 15);
} else {
self.flLayout.sectionInset = UIEdgeInsetsMake(0, 15, 0, 15);
}