分组 lambda

Question

如果我有这样的结构：

Batch  Amount
76  495.4
76  975.75
76  25
76  442.46
77  1335.12
77  2272.37
77  34.5
77  496.99
77  360
77  13
77  594.6

我想得到类似

Batch  Amount
76    1938.61
77    5106.58

表达式应该如何？

我是这样开始的：

batches.GroupBy(x => new { Batch = x.Batch, Amount = x.Amount });

但这并不是我正在寻找的东西。帮助我把它做好。谢谢

Answer 1

关闭。试试这个：

batches.GroupBy(x => x.Batch, x => x.Amount).Select(g => new {
    Batch = g.Key,
    Amount = g.Sum()
});

Answer 2

查询将如下所示：

var bs = from s in batches
            group s by s.Batch into g
            select new { Batch = g.Key, Amount = g.Sum(p => p.Amount) };

虽然我不知道更新的 lambda 等价物是什么

：

Resharper 帮助很大！ :)

var batches = bs .GroupBy(s => s.Batch).Select(
                g => new {Batch = g.Key, Amount = g.Sum(p => p.Amount)});