在c#中如何实现自定义的分组逻辑

在C#中，你可以通过实现IEnumerable<T>.GroupBy<TKey>方法来自定义分组逻辑。以下是一个示例：

using System; using System.Collections.Generic; using System.Linq;  class CustomGrouping {     static void Main()     {         var people = new List<Person>         {             new Person { Name = "Alice", Age = 30, City = "New York" },             new Person { Name = "Bob", Age = 25, City = "San Francisco" },             new Person { Name = "Charlie", Age = 30, City = "New York" },             new Person { Name = "David", Age = 28, City = "San Francisco" },             new Person { Name = "Eva", Age = 25, City = "Los Angeles" }         };          // 自定义分组逻辑         var groupedPeople = people.GroupBy(p => p.City, (city, group) =>         {             return new             {                 City = city,                 People = group.OrderBy(p => p.Name).ToList()             };         }).ToList();          // 输出结果         foreach (var group in groupedPeople)         {             Console.WriteLine($"City: {group.City}");             foreach (var person in group.People)             {                 Console.WriteLine($"  {person.Name}, {person.Age}");             }         }     } }  class Person {     public string Name { get; set; }     public int Age { get; set; }     public string City { get; set; } } 

在这个示例中，我们首先创建了一个Person列表。然后，我们使用GroupBy方法按城市对人员进行分组。我们提供了一个自定义的匿名类型作为分组的键，并将分组后的结果存储在一个名为groupedPeople的列表中。最后，我们遍历groupedPeople列表并输出每个分组的城市和人员信息。