C# - Lambda -对包含嵌套列表对象的列表数据进行分组

// 定义一个包含嵌套列表对象的数据结构
class Person
{
    public string Name { get; set; }
    public int Age { get; set; }
    public List<string> Hobbies { get; set; }
}

// 创建示例数据
List<Person> people = new List<Person>
{
    new Person { Name = "Alice", Age = 25, Hobbies = new List<string> { "Reading", "Cooking" } },
    new Person { Name = "Bob", Age = 30, Hobbies = new List<string> { "Gardening", "Painting" } },
    new Person { Name = "Charlie", Age = 25, Hobbies = new List<string> { "Reading", "Swimming" } }
};

// 使用Lambda表达式和LINQ对数据进行分组
var groupedData = people
    .SelectMany(p => p.Hobbies, (person, hobby) => new { person, hobby }) // 展开嵌套列表
    .GroupBy(x => x.hobby) // 按照爱好进行分组
    .Select(g => new { Hobby = g.Key, People = g.Select(x => x.person) }); // 构造结果

// 输出分组结果
foreach (var group in groupedData)
{
    Console.WriteLine("Hobby: " + group.Hobby);
    foreach (var person in group.People)
    {
        Console.WriteLine(" - " + person.Name);
    }
    Console.WriteLine();
}