UICollectionview cell之间有空隙，请问怎么解决

Question

前辈们好 请教下
我有个一个collectionview a section水平摆4个cell，b section水平摆3个cell，同一个section的cell互相之间都没有间距，sectionInset也是(0,0,0,0)

cell的size是这样

+(CGSize)cellSizeWithEachLineCount:(NSInteger)count{
    CGFloat w = screenWidth / (float)count;
    CGFloat h = 80;
    return CGSizeMake(w,h);
}

UICollectionViewDelegateFlowLayout协议如下：

-(UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section{

    UIEdgeInsets inset = UIEdgeInsetsZero;
    switch (section) {
        case 0:
            inset = UIEdgeInsetsMake(0, 0, 0, 0);
            break;
        case 1:
            inset = UIEdgeInsetsMake(0, 0, 0, 0);
            break;
        case 2:
            inset = UIEdgeInsetsMake(0, 0, 0, 0);
            break;
        case 3:
            inset = UIEdgeInsetsMake(8, 0, 0, 0);
            break;
        default:
            break;
    }
    
    return inset;
}

-(CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section{

    return 0.0;
}

-(CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section{

    return 0.0;
}

但a section有间隙，b section没有，如下图(待付款与待发货之间，待收货与待评价之间)

请问怎么回事？应该怎么解决？

Answer 1

把背景调成白色就看不出来了...233333