C带后编码问题的Web请求

在msdn站点上有一个 example of some C# code 这显示了如何使用发布的数据进行Web请求。以下是该代码的摘录:

WebRequest request = WebRequest.Create ("http://www.contoso.com/PostAccepter.aspx ");
request.Method = "POST";
string postData = "This is a test that posts this string to a Web server.";
byte[] byteArray = Encoding.UTF8.GetBytes (postData); // (*)
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = byteArray.Length;
Stream dataStream = request.GetRequestStream ();
dataStream.Write (byteArray, 0, byteArray.Length);
dataStream.Close ();
WebResponse response = request.GetResponse ();
...more...

标线 (*) 这句台词让我困惑。数据不应该使用urlencode方法而不是utf8编码吗?这不是什么 application/x-www-form-urlencoded 暗示?