Problem creating folders in sharepoint online using REST API & C# using access token approach

Question

I was trying to test creating folder under root folder in sharepoint online using access token and REST API using HTTPWebRequest classes from console application.

I don't want to use any sharepoint assemblies as since I can't actually use this in my final code. But always getting 403 Forbidden exception when getting the response.

Can any one kindly suggest if any useful reference documentation for this issue?

Code I am using:

void CreateFolder(string token, string library, string folder)
                {
                    string sharePointSite = "https://xxx.sharepoint.com/sites/xxx";                
                    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(sharePointSite + "/_api/lists/getByTitle('" + library + "')");
                    //HttpWebRequest request = (HttpWebRequest)WebRequest.Create(sharepointURL + "/_api/lists/getByTitle('" +library + "')/rootfolder/folders/add(url ='" +folder + "')");
                    request.Method = "POST";
                    request.Accept = "application/json; odata=verbose";
                    //request.Headers.Add(HttpRequestHeader.Authorization, "Bearer" + token);
                    myWebRequest.Headers.Add("Authorization", "Bearer");
                    ASCIIEncoding encoding = new ASCIIEncoding();
                    //byte byte1 = encoding.GetBytes(request);
                    request.ContentLength = 0;
                    Console.WriteLine(request);

                    try
                    {
                        if (request.GetResponse().ToString() != null)
                        {
                            using (WebResponse response = request.GetResponse())
                            {
                                Console.WriteLine(response);
                                Console.ReadKey();
                            }
                            // Do something if the resource has changed.

                        }
                    }
                    catch (WebException wex)
                    {

                        HttpWebResponse httpResponse = wex.Response as HttpWebResponse;
                        if (httpResponse.StatusCode != (HttpStatusCode.NotModified))
                        {                            // resource was not modified.
                            Console.WriteLine("Error occured from line 195");
                        }
                        // Something else happened. Rethrow or log.
                        //throw;
                    }
                    catch (Exception ex)
                    {    // Something else happened. Rethrow or log
                        Console.WriteLine("Error occured from line 203");                        
                    }

Answer 1

You need to Authenticate before making POST requests. So, try using below code:

public static void CreateFolder()
 {
             string result = string.Empty;
             Uri uri = new Uri("http://basesmc15/_api/web/folders");
             HttpWebRequest wreq = (HttpWebRequest)WebRequest.Create(uri);
             wreq.Credentials = CredentialCache.DefaultNetworkCredentials;

             wreq.Method = "POST";
             wreq.Accept = "application/json; odata=verbose";
             wreq.ContentType = "application/json; odata=verbose";
             wreq.Headers.Add("X-HTTP-Method", "POST");
             wreq.Headers.Add("X-RequestDigest", GetFormDigest());

             string stringData = "{'__metadata': { 'type': 'SP.Folder' }, 'ServerRelativeUrl': '/shared documents/foldername2'}";
             wreq.ContentLength = stringData.Length;
             StreamWriter writer = new StreamWriter(wreq.GetRequestStream());
             writer.Write(stringData);
             writer.Flush();

             WebResponse wresp = wreq.GetResponse();
             using (StreamReader sr = new StreamReader(wresp.GetResponseStream()))
             {
                 result = sr.ReadToEnd();
             }
}

Source: Not able to create a Folder in sharepoint 2013 online.

Answer 2

I was able to achieve using below approach, posting so that some one can make use of this:

public void CreateFolder(string sharePointSite, string token, string library, string folder,Guid entityID)
        {
                   if (library == "contact")
            {
                Entity contact = _service.Retrieve("contact", entityID, new ColumnSet("suffix"));            
                string knownas = contact.GetAttributeValue<string>("suffix");
                knownas = knownas.Replace("/", "").Replace("&","");//replaced explicity as WebUtility.UrlEncode doesn't handle                
                folder = folder + "_" + WebUtility.UrlEncode(knownas);                
            }
            string result = string.Empty;
            StringBuilder sb = new StringBuilder();
            sb.Append(sharePointSite);
            sb.Append("_api/web/GetFolderByServerRelativePath(decodedUrl='");
            sb.Append(library);
            sb.Append("')/Folders");
            Uri uri = new Uri(sb.ToString().Replace("{", "").Replace("}", ""));            
            HttpWebRequest wreq = (HttpWebRequest)WebRequest.Create(uri);
            wreq.Headers.Add("Authorization", "Bearer " + token);
            wreq.Method = "POST";
            wreq.ContentType = "application/json";
            string postData = "{'ServerRelativeUrl':'folder'}";
            postData = postData.Replace("folder", folder);            
            byte[] byteArray = Encoding.UTF8.GetBytes(postData);
            wreq.ContentLength = postData.Length;
            Stream dataStream = wreq.GetRequestStream();
            dataStream.Write(byteArray, 0, byteArray.Length);
            dataStream.Close();
            WebResponse wresp = null;
            try
            {
                wresp = wreq.GetResponse();
                using (wresp = wreq.GetResponse())
                {
                    dataStream = wresp.GetResponseStream();
                    StreamReader reader = new StreamReader(dataStream);
                    string responseFromServer = reader.ReadToEnd();
                    reader.Close();
                }
            }
            catch (WebException wex)
            {
                HttpWebResponse httpResponse = wex.Response as HttpWebResponse;
                createlog(_service, "Error occured" + wex.ToString());
                throw new InvalidPluginExecutionException("Exception occured while creating record" + wex.ToString());
            }
}