相关疑难解决方法(0)

我得到了这个程序,它给我语法错误"System.Threading.Tasks.task不包含Run的定义."

我正在使用VB 2010 .NET 4.0任何想法？在.net 4.0中运行的任何替换？

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace ChatApp
{
class ChatProg
{
    static void Main(string[] args)
    {
        Task<int> wakeUp = DoWorkAsync(2000,"Waking up");
        Task.WaitAll(wakeUp);
    }

    static Task<int> DoWorkAsync(int milliseconds, string name)
    {

        //error appears below on word Run
        return Task.Run(() =>
            {
                Console.WriteLine("* starting {0} work", name);
                Thread.Sleep(milliseconds);
                Console.WriteLine("* {0} work one", name);
                return 1;
            });
    }
}
}