c# - 此 Linq 查询等效的 C# 扩展方法是什么？

Question

在 this example:

public void Linq40()
{
    int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };

    var numberGroups =
        from n in numbers
        group n by n % 5 into g
        select new { Remainder = g.Key, Numbers = g };

    foreach (var g in numberGroups)
    {
        Console.WriteLine("Numbers with a remainder of {0} when divided by 5:",
            g.Remainder);

        foreach (var n in g.Numbers)
        {
            Console.WriteLine(n);
        }
    }
}

什么是纯 C# 等价物？我明白了……

var numberGroups = numbers.GroupBy(n => n % 5)...

但是 into 子句有点神秘，我不知道如何从 Select 中获取 Key .

Answer 1

GroupBy返回 IEnumerable<T>的 <IGrouping<TKey, TSource> .有了这个，您可以执行第二个 Select 操作，它返回与上面完全相同的值:

var numberGroups = numbers.GroupBy(n => n % 5)
                          .Select(g => new { Remainder = g.Key, Numbers = g });