Not getting response when I call "2/files/listfolder" method

How i can uplaod a new version for any file using API.

I have try  

  string data = String.Format("/2/files/upload");
            string responseStr = ";

            RestRequest request = FormRequest(Method.POST, data, false);
            IRestResponse response = new RestSharp.RestResponse();

string fullPathToUpload = metadataJson.path;
                string path = string.Format("{1}\"path\":\"{0}\",\"mode\":{1}\".tag\":\"update\",\"update\":\"{3}\"{2}{2}", fullPathToUpload, "{", "}", rev);
                request.AddHeader("Dropbox-API-Arg", path);
                request.AddHeader("Content-Type", "application/octet-stream;");
                request.AddParameter("application/octet-stream", externalFile.InputBytes, ParameterType.RequestBody);
                response = executeRequestContent(request);
                responseStr = response.Content;
                status = response.StatusDescription;

but found nothing got changes in Dropbox account. Plz help.

What's the response from the API to this call?

I got file information in response. but when when i check it in my Dropbox account and file version not getting update and file modified time remain unchanged.

Are you attempting to upload the same exact data as is contained in the current version? Uploading an identical version of a file doesn't create a new revision.

Thanks, I got it.