使用Socket.ReceiveFrom如何一次性收取socket缓存数据

Question

使用如下代码，发送UDP数据：

using System;
using System.Collections.Generic;
using System.Text;
using System.Net;
using System.Net.Sockets;
using System.IO;

namespace UDPClient
{
  class Program
  {
    static void Main(string[] args)
    {
      FileStream FS=new FileStream("c:\\ttt.dat",FileMode.Open);
      BinaryReader BR=new BinaryReader(FS,Encoding.Default);


      byte[] data = new byte[1024];
      string input, stringData;

      //构建TCP 服务器


      //设置服务IP，设置TCP端口号
      IPEndPoint ipep = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 8001);

      //定义网络类型，数据连接类型和网络协议UDP
      Socket server = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);

      server.Bind(new IPEndPoint(IPAddress.Parse("127.0.0.1"), 9000));

      while (FS.Position<FS.Length)
      {
        if (FS.Length - FS.Position > 100)
          data = BR.ReadBytes(100);
        else
          data = BR.ReadBytes((int)(FS.Length - FS.Position));
        server.SendTo(data, data.Length, SocketFlags.None, ipep);
      }

      server.Close();
    }

  }
}

使用如下代码，接收UDP数据：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.Net.Sockets;

namespace UDP
{
  class Program
  {
    static void Main(string[] args)
    {
      int recv;
      byte[] data;

      //构建TCP 服务器

      //得到本机IP，设置TCP端口号     
      IPEndPoint ipep = new IPEndPoint(IPAddress.Any, 8001);
      Socket newsock = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);

      //绑定网络地址
      newsock.Bind(ipep);

      IPEndPoint sender = new IPEndPoint(IPAddress.Any, 0);
      EndPoint Remote = (EndPoint)(sender);


      while (true)
      {
        if (newsock.Available == 0)
        {
          System.Threading.Thread.Sleep(1);
          continue;
        }
        int bufferSize = newsock.Available;
        data = new byte[bufferSize];

        recv = newsock.ReceiveFrom(data,bufferSize ,SocketFlags.None, ref Remote);
      }
    }

  }
}

想一次性把socket缓存中已有的数据都收完，但是发现不行，指定了bufferSize也不行，接收端的recv始终等于100，和发端每次发送的数据一样，即使newsock.Available=1000，每次也只收100字节，要分10此才能把数据收完，这是为什么呢？该如何解决？谢谢！