LINQ，简化表达式-取时取和不超过给定值 [英] LINQ, simplifying expression - take while sum of taken does not exceed given value

问题描述

给出这样的设置..

class Product {
   int Cost;
   // other properties unimportant
}

var products = new List<Product> {
    new Product { Cost = 5 },
    new Product { Cost = 10 },
    new Product { Cost = 15 },
    new Product { Cost = 20 }
};

var credit = 15;

假设列表将按照给定的顺序排序.我希望基本上遍历列表中的每个项目，保持成本的总和，并在总成本不超过credit的情况下继续推出产品.

Assume that the list will be sorted in the given order. I wish to basically iterate over each item in the list, keep a summed value of cost, and keep getting products out as long as the total cost does not exceed credit.

我可以使用一些循环和东西来做到这一点，但是我想知道是否有一种方法可以将其压缩为一个更简单的LINQ查询.

I can do this with some loops and stuff, but I was wondering if there is a way to compact it into a simpler LINQ query.

推荐答案

不是完全" linq，因为它需要一个额外的变量，但这是我最容易想到的:

Not "fully" linq, because it needs one extra variable, but it is the easiest I could think of:

int current=0;
var selection = products.TakeWhile(p => (current = current + p.Cost) <= credit);

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