List<string>里 每个元素重复了多少次

     static void Main(string[] args)

        {

            List<string> list = new List<string>();

            list.Add("aaa");

            list.Add("aa");

            list.Add("dd");

            list.Add("aaa");

            list.Add("dd");

            list.Add("aa");

            list.Add("aaa");

            int a = RepeatTimes(list, "aaa");//某个对象重复有多少次

            //打印出重复多少次

            foreach (var item in list.GroupBy(s => s))

            {

                Console.WriteLine("{0}:{1}次", item.Key, item.Count());

            }

        }

        /// <summary>

        /// 某个元素重复次数

        /// </summary>

        /// <param name="L"></param>

        /// <param name="text"></param>

        /// <returns></returns>

        private static int RepeatTimes(List<string> list, string text)

        {

            int num = 0;

            foreach (string str in list)

                if (str == text)

                    num++;

            return num;

        }