asp.net web api - WebRequest POST json parameter showing as Null on WebAPI -

i have webrequest executing through windows ce project. able send through , able see hitting webapi. issue when request comes through, parameter null.

web api

 [route("")]     public ihttpactionresult post([frombody] stopinfo stopinfo)     {         try         {             _scannerservice.addstops(stopinfo);             return ok(stopinfo);          }         catch (exception ex)         {             //return request.createerrorresponse(httpstatuscode.badrequest, ex);             return null;         }     } 

webrequest

private void btnupload_click(object sender, eventargs e)     {          stopinfo s1 = new stopinfo();         s1.contactname = "test";         s1.companyname = "ignite";         s1.city = "katy";         s1.addr1 = "22908 mountain view";         s1.addr2 = "suite 300";         s1.state = "tx";         s1.zip = "77449";          string uploadurl = txtservertext.text + "/api/stops";          string json = jsonconvert.serializeobject(s1);          system.net.webrequest req = system.net.webrequest.create(uploadurl);          req.contenttype = "application/json";         req.method = "post";          byte[] bytes = system.text.encoding.ascii.getbytes(json);         req.contentlength = bytes.length;         system.io.stream os = req.getrequeststream();         os.write(bytes, 0, bytes.length); //push out there         os.close();         system.net.webresponse resp = req.getresponse();          system.io.streamreader sr =               new system.io.streamreader(resp.getresponsestream());      } 

try use cast when creating httpwebrequest object, below example:

  httpwebrequest req =              (httpwebrequest)webrequest.create((uploadurl.tostring()); 

also add below properties httpwebrequest object

req.timeout = yourwebrequesttimeoutlimit     req.keepalive = false     req.accept = "application/json"     req.credentials = new networkcredential(username, password)