C# 一个Task的输出作为另一个Task的输入

using System;
using System.Threading;
using System.Threading.Tasks;

namespace ConsoleApp3
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Passing the result of one task as an input into another");
            var task = Task.Factory.StartNew(CallWebService)
                .ContinueWith(previousTask => CallStoreProcedure(previousTask.Result));
            Console.WriteLine($"Result:{task.Result}");
        }

        static decimal CallWebService()
        {
            Console.WriteLine("Starting to call web service...");
            Thread.Sleep(new Random().Next(2000, 4000));
            Console.WriteLine("Finished call to web service");
            return 89.99M;
        }


        static string CallStoreProcedure(decimal amount)
        {
            Console.WriteLine("Starting to stored procedure");
            Thread.Sleep(new Random().Next(2000, 4000));
            Console.WriteLine("Finished call to stored procedure");
            return $"12 produects cost more than {amount:C}";
        }
    }
}