使用Linq对包含列表字段的对象进行分组

// 定义包含列表字段的对象
class Person
{
    public string Name { get; set; }
    public List<string> Hobbies { get; set; }
}

// 创建对象集合
List<Person> people = new List<Person>
{
    new Person { Name = "Alice", Hobbies = new List<string> { "Reading", "Cooking" } },
    new Person { Name = "Bob", Hobbies = new List<string> { "Sports", "Gaming" } },
    new Person { Name = "Charlie", Hobbies = new List<string> { "Reading", "Music" } }
};

// 使用Linq对对象进行分组
var groupedPeople = people
    .SelectMany(p => p.Hobbies, (person, hobby) => new { Person = person, Hobby = hobby })
    .GroupBy(x => x.Hobby)
    .Select(g => new { Hobby = g.Key, People = g.Select(x => x.Person) });

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