asp.net mvc - C# MVC - Creating and uploading a zip file to FTP -

i creating xml file using following 2 methods:

public string getxmlstringfromfeedmodel<t>(t feedmodel)     {         var builder = new stringbuilder();         using (stringwriter writer = new encodingstringwriter(builder, encoding.utf8))         {             xmlserializer serializer = new xmlserializer(typeof(t));             serializer.serialize(writer, feedmodel);             return writer.getstringbuilder().tostring();         }      }    public filecontentresult getxmlfilefromxmlstring(string xmlstring, string filename )     {         return new filecontentresult(encoding.utf8.getbytes(xmlstring), "application/xml") { filedownloadname = filename };     } 

i zip file method

 public filecontentresult zipfile(filecontentresult file, string filename)     {         using (var compressedfilestream = new memorystream())         {             //create archive , store stream in memory.             using (var ziparchive = new ziparchive(compressedfilestream, ziparchivemode.update, false))             {                  //create zip entry                  var zipentry = ziparchive.createentry(filename);                  //get stream of file                 using (var originalfilestream = new memorystream(file.filecontents))                 {                     using (var zipentrystream = zipentry.open())                     {                         //copy attachment stream zip entry stream                         originalfilestream.copyto(zipentrystream);                     }                 }             }              return new filecontentresult(compressedfilestream.toarray(), "application/zip") { filedownloadname = filename + ".zip" };         }     } 

then trying upload zipped file ftp server -

        var model = getmodel();         var xmlstring = getxmlstringfromfeedmodel(model);         var xmlfile = getxmlfilefromxmlstring(xmlstring);         var zipped = zipfile(xmlfile);          var credentials = getfeedcredentials(feedprovider);         var memstream =  new memorystream(zipped.filecontents)         string filename = getfilenameforprovider(feedprovider);          ftpwebrequest request = (ftpwebrequest)webrequest.create(credentials.url + "/" + filename);         request.method = webrequestmethods.ftp.uploadfile;          request.credentials = new networkcredential(credentials.username, credentials.password);          var requeststream = request.getrequeststream();         memstream.copyto(requeststream);         memstream.close();         requeststream.close();         ftpwebresponse response = (ftpwebresponse)request.getresponse();          return response; 

the file uploaded , not empty (as looks around expected size) when copy ftp server computer , try open it, corrupt (error message, "file not readable, try password")

i can't see i'm doing wrong , have been struggling solve couple of days.