static void Main(string[] args)
{
    int order = 0;//, -1 for exit , 0 for initialize
    int ordermax = 0;//最大编号
    ParameterizedThreadStart threadProc = p =>
        {
            if (!(p is int)) return;
            int myOrder = (int)p;
            object sync = new object();
            while (true)
            {
                lock (sync)//同步线程
                {
                    if (order != myOrder)//判断状态机当前状态是否是到自己执行
                    {
                        Thread.Sleep(50);//阻塞自己线程50毫秒后继续下一次检测
                        continue;
                    }
                    Console.WriteLine(p);//实际操作
                    order++;//在lock块中，安全的操作状态
                    if (order > ordermax) order = 1;//循环状态
                }
                Thread.Sleep(50);
            }
        };
    new Thread(threadProc).Start(1);//启动1个线程，编号1
    new Thread(threadProc).Start(2);//启动1个线程，编号2
    new Thread(threadProc).Start(3);//启动1个线程，编号3
    new Thread(threadProc).Start(4);//启动1个线程，编号4
    ordermax = 4;//最大值4
    order = 1;//当前状态1，开始启动
    Console.ReadKey();
}

------解决方案--------------------
thread.Join(); 不就可以了么
C# code
        public const int Repetitions = 10000;

        public static void Main()
        {
            //Thread thread = new Thread(DoWork);
            //thread.Start(".");
            //thread.Join();
            //for (int count = 0; count < Repetitions; count++)
            //{
            //    Console.Write('-');
            //}
            Thread thread;
            for (int i = 0; i < 3; i++)
            {
                thread = new Thread(DoWork);
                if (i == 0)
                {
                    thread.Start(".");
                }
                else if (i == 1)
                {
                    thread.Start("-");
                }
                else if (i == 2)
                {
                    thread.Start("*");
                }
                else {
                    thread.Start("&");
                }
                thread.Join();
            }
            
            Console.ReadLine();
        }

        public static void DoWork(object state)
        {
            for (int count = 0; count < Repetitions; count++)
            {
                Console.Write(state);
            }
        }
    }