webDav列表出文件夾內容的時候，當需要代理時使用WebRequest 代替XMLHTTP30

System.Uri myURi = new System.Uri(remoteHost + dirname);

WebRequest req = WebRequest.Create(myURi);
req.Method = "PROPFIND";

req.Credentials = new NetworkCredential(user, password);//用户名,密码
req.Proxy = WebRequest.DefaultWebProxy; //使用默認IE代理
req.PreAuthenticate = true;
req.ContentType = "text/xml";
req.Headers.Add("Depth", "1,noroot");
Stream resStream = req.GetRequestStream();

string strXml;
strXml = "<?xml version=/"1.0/"?> ";
strXml += "<d:propfind xmlns:d=/"DAV:/">";
strXml += "<d:prop>";
strXml += "<d:iscollection/>";
strXml += "<d:getcontentlength/>";
strXml += "<d:getlastmodified/>";
strXml += "<d:displayname/>";
strXml += "</d:prop>";
strXml += "</d:propfind>";

byte[] reqXml = Encoding.Default.GetBytes(strXml);
resStream.Write(reqXml, 0, reqXml.Length);
resStream.Flush();
resStream.Close();
WebResponse res = req.GetResponse();
Stream responseStream = res.GetResponseStream();