实体类：

public class Person    {        public int ID { get; set; }        /// <summary>        /// 姓名        /// </summary>        public string Name { get; set; }        /// <summary>        /// 住址        /// </summary>        public string Addr { get; set; }        /// <summary>        /// 国家        /// </summary>        public string County { get; set; }        /// <summary>        /// 性别 F M        /// </summary>        public string  Sex { get; set; }    }








实现：

class Program    {        static void Main(string[] args)        {            var lst = new List<Person> {              new Person{ ID=1,Name="AA", County="CN", Addr="JD1", Sex="F"},             new Person{ ID=2,Name="BB", County="CN", Addr="JD1", Sex="M"},             new Person{ ID=3,Name="CC", County="US", Addr="JD2", Sex="F"},             new Person{ ID=4,Name="DD", County="US", Addr="JD2", Sex="M"},             new Person{ ID=5,Name="EE", County="HK", Addr="JD3", Sex="F"},             new Person{ ID=6,Name="FF", County="HK", Addr="JD4", Sex="M"},             new Person{ ID=7,Name="GG", County="HK", Addr="JD5", Sex="F"},            };              var gps_1 = lst.GroupBy(x => (GetUnicIdetity(x.County)));//仅仅按照国家分组            var gps_2 = lst.GroupBy(x => GetUnicIdetity(x.County, x.Sex));//按照国家+性别进行分组             Console.WriteLine("单属性分组：");            foreach (var g in gps_1)            {                Console.WriteLine(g.Key);            }            Console.WriteLine("下面是按照符合组键进行的分组：");            foreach (var g in gps_2)            {                Console.WriteLine(g.Key);            }              Console.ReadKey();        }         private static string GetUnicIdetity(params object[] paras)        {            StringBuilder sb_result = new StringBuilder("");            char spliterChar=‘-‘;            if (null!=paras&&paras.Count()>0)            {                foreach (var item in paras)                {                    sb_result.Append(item).Append(spliterChar);                }                //移除掉最后一个-，也可以不移除                if (sb_result.Length>1)                {                    sb_result.Remove(sb_result.Length - 1, 1);                }             }            return sb_result.ToString();        }    }

对集合进行多条件属性分组