static void Main(string[] args)
        {   
            //定义两个哈希集合以及其中一个集合的子集
            HashSet<int> hashSet1 = new HashSet<int>() { 1, 2, 3, 4, 5 };
            HashSet<int> hashSet2 = new HashSet<int>() { 6, 7, 8, 9, 10 };
            HashSet<int> hashSet1Sub = new HashSet<int>() { 4, 5 };
            HashSet<int> hashSetAll = new HashSet<int>();

            string message = String.Empty;
            bool result = false;

            #region Hash集合元素唯一性体现
            result = hashSet1.Add(1);    //集合1中添加重复元素
            if (result)
            {
                message = "Hash集合已存在该元素";
            }
            else
            {
                message = "元素添加成功";               
            }
            Console.WriteLine(message);
            #endregion

            #region Hash表子集、交集判断
            result = hashSet1.IsSubsetOf(hashSet2);
            if (result)
            {
                message = "Hash集合2是集合1的子集";
            }
            else
            {
                message = "Hash集合2不是集合1的自己";
            }
            Console.WriteLine(message);

            result = hashSet1.Overlaps(hashSet2);
            if (result)
            {
                message = "Hash集合1和Hash集合2存在交集";
            }
            else
            {
                message = "Hash集合1和hash集合2不存在交集";
            }

            result = hashSet1.IsSupersetOf(hashSet2);
            if (result)
            {
                message = "集合1完全包含集合2";
            }
            else
            {
                message = "集合1不完全包含集合2";
            }
            #endregion

            #region 集合的初始化
            hashSetAll = new HashSet<int>(hashSet1);
            hashSetAll.UnionWith(hashSet2);
            hashSetAll.UnionWith(hashSet1Sub);

            message = "输出所有集合的元素";
            Console.WriteLine(message);
            foreach (int item in hashSetAll)
            {
                Console.WriteLine(item);
            }
            #endregion

            #region 排除元素
            hashSetAll.ExceptWith(hashSet2);
            message = "排除了集合2并输出";
            Console.WriteLine(message);
            foreach (var item in hashSetAll)
            {
                Console.WriteLine(item);
            }
            #endregion

            Console.ReadKey();
        }