int[] list = { 1, 2, 3, 5, 8, 9, 10, 11, 12, 13,  15, 16, 19, 21, 22, 23 };
            var query = list.OrderBy(p => p).Aggregate<int, List<List<int>>>(null, (m, n) =>
            {
                if (m == null) return new List<List<int>>() { new List<int>() { n } };
                if (m.Last().Last() != n - 1)
                {
                    m.Add(new List<int>() { n });
                }
                else
                {
                    m.Last().Add(n);
                }
                return m;
            });
            string timeStr = "";
            foreach (var p in query)
            {
                if (p.First() == p.Last())
                {
                    timeStr += p.First()+ "、";
                }
                else
                {
                    timeStr += p.First()+ "-" + p.Last() + "、";
                }
            }
            Console.WriteLine(timeStr);

结果 1-3、5、8-13、15-16、19、21-23、