MSDN里的socket.send(4参数)和(5参数)示例是一样的？
http://msdn.microsoft.com/zh-cn/library/ms145162.aspx 5参数
http://msdn.microsoft.com/zh-cn/library/4t14718h.aspx 4参数

都是
// Displays sending with a connected socket
// using the overload that takes a buffer, offset, message size, and socket flags.
public static int SendReceiveTest4(Socket server)
{
  byte[] msg = Encoding.UTF8.GetBytes("This is a test");
  byte[] bytes = new byte[256];
  try 
  {
  // Blocks until send returns.
  int byteCount = server.Send(msg, 0, msg.Length, SocketFlags.None);
  Console.WriteLine("Sent {0} bytes.", byteCount);

  // Get reply from the server.
  byteCount = server.Receive(bytes, 0, server.Available, 
  SocketFlags.None);

  if (byteCount > 0)
  Console.WriteLine(Encoding.UTF8.GetString(bytes));
  }
  catch (SocketException e)
  {
  Console.WriteLine("{0} Error code: {1}.", e.Message, e.ErrorCode);
  return (e.ErrorCode);
  }
  return 0;
}

让我对函数重载起了疑惑....
5参数的示例也是4参数的...那如果是msdn错了？那正确的是这样的？
public static int SendReceiveTest5(Socket server)
{
  byte[] msg = Encoding.UTF8.GetBytes("This is a test");
  byte[] bytes = new byte[256];
  SocketError errormsg;
  try 
  {
  // Blocks until send returns.
  int byteCount = server.Send(msg, 0, msg.Length, SocketFlags.None,out errormsg);
  Console.WriteLine("Sent {0} bytes.", byteCount);
  // Get reply from the server.
  byteCount = server.Receive(bytes, 0, server.Available, 
  SocketFlags.None);

  if (byteCount > 0)
  Console.WriteLine(Encoding.UTF8.GetString(bytes));
  }
  catch (SocketException e)
  {
  Console.WriteLine("{0} Error code: {1}.", e.Message, e.ErrorCode);
  return (e.ErrorCode);
  }
  return 0;
}

------解决方案--------------------
楼主太较真了。显然这两个页面都用了相同的一段示例代码，SendReceiveTest4未必就一定表示“4参数”示例，或者仅仅是指“第四个”示例呢？最重要是看明白了就好
MSDN上有些内容确实有误，不过主要是翻译成中文后的问题比较多
------解决方案--------------------
例子有问题，5参数有一个out errormsg，错误信息