线程：异步任务：从Thread到Task

class InvokingAnAsynchronousTask
    {
        public static void Main()
        {
            const int repetitions = 1000;
            // Use Task.Factory.StartNew<string>() for
            // TPL prior to .NET 4.5
            Task task = Task.Run(() =>
            {
                for (int count = 0; count < repetitions; count++)
                {
                    Console.Write('-');
                }
            });
            for (int count = 0; count < repetitions; count++)
            {
                Console.Write('+');
            }

            // Wait until the Task completes
            task.Wait();
            Console.WriteLine("主线程完成");
            Console.ReadKey();
        }
    }