关于线程lock的诡异错误，msdn中的C#编程指南里面的一个范例,程序红色部分为问题

Question

using System; using System.Threading; namespace LockTest{    class Account    {        private object thisLock = new object();        double balance;         Random r = new Random();        public int number = 0;         public Account(double Initial)        {            balance = Initial;        }        double WithDraw(double amount)        {                        if (balance < 0)                throw new Exception("余额为负");            lock (thisLock)            {                if (balance >= amount)                {                    number++;                    Console.WriteLine("number:" + number);                    Console.WriteLine("取款前余额:{0}", balance);                    Console.WriteLine("取款:{0}:", amount);                    balance -= amount;                    Console.WriteLine("取款后余额:{0}\n", balance);                    return amount;                }                else                {                    Console.WriteLine("余额不足");                    return 0;                }            }                   }        public void DoTransactions()        {            int num = 6;            for (int i = 0; i < num; i++)  //当num>=6时出现问题,没有打印"number:1",但num=1-5时是正常的。            {                WithDraw(r.Next(1, 100));            }                   }    }     class Program    {        static void Main(string[] args)        {            Thread[] threads = new Thread[10];            Account acc = new Account(10000);            for (int i = 0; i < 10; i++)            {                Thread t = new Thread(new ThreadStart(acc.DoTransactions));                threads[i]=t;                threads[i].Start();            }            //for (int i = 0; i < 10; i++)            //{            //    threads[i].Start();            //}        }    }}

Answer 1

 i < num ,而 num = 6

num > = 6 时, 退出 for 循环,WithDraw(r.Next(1, 100)); 就不执行了.

Answer 2

 我把你的代码运行了一下，没有任何问题，即使把num改成26也没有问题啊，不会出现你说的那种情况，你再试一下，是不是看错了

Answer 3

@码魔谷:CMD不够行输出.你把 Console.WriteLine 改成 Debug.WriteLine,然后从VS的输出窗口中查看结果.

Answer 4

非常感谢，在输出窗口看到了！