NSString *cellId = [NSString stringWithFormat:@"cellId%ld,%ld,%ld",(long)collectionView.tag,indexPath.section,indexPath.row];
[collectionView registerClass:[MTCameraStickerCell class] forCellWithReuseIdentifier:cellId];
MTCameraStickerCell *cell = (MTCameraStickerCell *)[collectionView dequeueReusableCellWithReuseIdentifier:cellId forIndexPath:indexPath];
给每个cell 标志唯一的id
