UICollectionView实现多选且组内单选

1、设置UICollectionView可以多选：self.collectionV.allowsMultipleSelection = YES;
2、在数据模型中添加select属性作为记录状态，添加indexPath属性作为拿去对应的Cell
3、取消选中：[collectionView deselectItemAtIndexPath:skut.indexPath animated:YES];
4、选中：[collectionView selectItemAtIndexPath:indexPath animated:YES scrollPosition:UICollectionViewScrollPositionNone];
5、获取所有选中的：NSArray * selectIndexPaths = collectionView.indexPathsForSelectedItems;

-(void)collectionView:(UICollectionView *)collectionView didDeselectItemAtIndexPath:(NSIndexPath *)indexPath{

    CommodityTypeCell * cell = (CommodityTypeCell*)[collectionView cellForItemAtIndexPath:indexPath];
    [cell setBackgroundColor:[UIColor grayColor]];

    if (collectionView.indexPathsForSelectedItems.count!=self.commodity.proAttributeList.count) {
        // 做对应的业务处理（比如商品分类标签，改为显示价格区间）
    }
}

-(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath{
    
//     取消当前组内已选中的
    CommodityType * type = self.commodity.proAttributeList[indexPath.section];
    for (SkuList * skut in type.attribute_vals) {
        if (skut.select == YES) {
            skut.select = NO;
            CommodityTypeCell * oldCell = (CommodityTypeCell*)[collectionView cellForItemAtIndexPath:skut.indexPath];
            [oldCell setBackgroundColor:[UIColor grayColor]];
            [collectionView deselectItemAtIndexPath:skut.indexPath animated:YES];// 取消选中
        }
    }
    
    // 选中当前点击的item
    SkuList * sku = type.attribute_vals[indexPath.item];
    sku.select = YES;
    sku.indexPath = indexPath;
    CommodityTypeCell * cell = (CommodityTypeCell*)[collectionView cellForItemAtIndexPath:indexPath];
    [collectionView selectItemAtIndexPath:indexPath animated:YES scrollPosition:UICollectionViewScrollPositionNone];// 需要添加选中
    [cell setBackgroundColor:[UIColor orangeColor]];

    if (collectionView.indexPathsForSelectedItems.count!=self.commodity.proAttributeList.count) {
        // 做对应的业务处理（比如商品分类标签，显示该商品的唯一价格和库存）
    }
}