c#比较器 排序

class Program
    {
        static void Main(string[] args)
        {
            Data[] array = new Data[] { new Data() { a = 1 }, new Data() { a = 3 }, new Data() { a = 2 } };
            Array.Sort(array,new MyComparer());
            foreach (var item in array)
            {
                Console.WriteLine(item.a);
            }
            Console.ReadKey();
        }
    }
    class Data
    {
        public int a{get;set;}
    }
    class MyComparer : IComparer {
        #region IComparer Members
        public int Compare(object x, object y)
        {
            Data a = x as Data;
            Data b = y as Data;
            if (a.a > b.a)
                return 1;
            else if (a.a == b.a)
                return 0;
            else
                return -1;
        }
        #endregion
    }