c#4.0多线程的使用

  class Account    {        public int Balance        {            get;            set;        }    }       List<Task> tasks = new List<Task>();            for (int i = 0; i < 4; i++)            {                            tasks.Add(Task.Factory.StartNew(() =>                {                    for (int j = 0; j < 10; j++)                    {                        lock (account)                        {                            account.Balance++;                        }                                           }                }));            }