C# LINQ 表达式变得相当长

Question

所以，我的代码中有一个对象(容器)列表，我想检查我要添加的容器是否会影响每个容器顶部的最大重量(container.MaxWeightOnTop).我创建了这个函数:

    private bool TooMuchWeight(Container referenceContainer)
    {
        var tempList = _containers;
        tempList.Add(referenceContainer);
        SortStack(tempList);

        foreach (var container in tempList)
        {
            var index = tempList.FindIndex(c => c == container);
            var weightOnContainer = tempList.Where(c => tempList.FindIndex(i => i == container) > index)
                .Sum(c => container.Weight);

            if (weightOnContainer > Container.MaxWeightOnTop)
                return false;
        }

        return true;
    }

如您所见，它变得相当长，我的 IDE 甚至建议将此 LINQ 表达式用于整个 foreach 循环:

 return (from container in tempList
            let index = tempList.FindIndex(c => c == container)
            select tempList.Where(c => tempList.FindIndex(i => i == container) > index)
                .Sum(c => container.Weight)).All(weightOnContainer => weightOnContainer <= Container.MaxWeightOnTop);

即使我使用 .GetRange 函数，它仍然很长:

return tempList
            .Select(container =>
                tempList.GetRange(tempList.FindIndex(c => c == container), Length).Sum(c => c.Weight))
            .All(weightOnContainer => weightOnContainer <= Container.MaxWeightOnTop);

问题:是否可以压缩这个表达式？

Answer 1

就可读性和性能而言，我认为您的代码可以利用索引 Enumerable.Select重载和值元组:

    var tempList = _containers;
    tempList.Add(referenceContainer);
    SortStack(tempList);
    var indexed = tempList.Select((container, index) => (container, index)).ToList();
    foreach (var (container, index) in indexed)
    {
        var weightOnContainer = indexed
            .Where((c, i) => i > index)
            .Sum((c, i) => c.Weight);

        if (weightOnContainer > Container.MaxWeightOnTop)
            return false;
    }

同样在原始版本中 .Sum(c => container.Weight) 子句对我来说看起来有点古怪，不应该是 .Sum(c => c.Weight) ？