C＃Linq Group By在多个列上

一尘不染

C＃Linq Group By在多个列上

public class ConsolidatedChild
{
public string School { get; set; }
public string Friend { get; set; }
public string FavoriteColor { get; set; }
public List Children { get; set; }
}

public class Child
{
    public string School { get; set; }
    public string Name { get; set; }
    public string Address { get; set; }
    public string Friend { get; set; }
    public string Mother { get; set; }
    public string FavoriteColor { get; set; }
}

给定以上两个类，我想使用LINQ从列表创建一个列表，该列表按School，Friend和FavoriteColor属性分组。LINQ有可能吗？

请忽略属性，编写代码只是为了帮助解决该问题。

阅读 659

2020-05-19

共1个答案

一尘不染

简单：

var consolidatedChildren =
    from c in children
    group c by new
    {
        c.School,
        c.Friend,
        c.FavoriteColor,
    } into gcs
    select new ConsolidatedChild()
    {
        School = gcs.Key.School,
        Friend = gcs.Key.Friend,
        FavoriteColor = gcs.Key.FavoriteColor,
        Children = gcs.ToList(),
    };

var consolidatedChildren =
    children
        .GroupBy(c => new
        {
            c.School,
            c.Friend,
            c.FavoriteColor,
        })
        .Select(gcs => new ConsolidatedChild()
        {
            School = gcs.Key.School,
            Friend = gcs.Key.Friend,
            FavoriteColor = gcs.Key.FavoriteColor,
            Children = gcs.ToList(),
        });

2020-05-19