How to call Spotify API from C #

Question

I am trying to call the spotify API with C #. Sorry, I'm already stuck in getting access token

This is how I tried to get it:

 private static async Task<string> GetAccessToken() { SpotifyToken token = new SpotifyToken(); string postString = string.Format("grant_type=client_credentials"); byte[] byteArray = Encoding.UTF8.GetBytes(postString); string url = "https://accounts.spotify.com/api/token"; WebRequest request = WebRequest.Create(url); request.Method = "POST"; request.Headers.Add("Authorization", "Basic {Encoded myClientIdXXX:myAppSecretYYY}"); request.ContentType = "application/x-www-form-urlencoded"; request.ContentLength = byteArray.Length; using (Stream dataStream = request.GetRequestStream()) { dataStream.Write(byteArray, 0, byteArray.Length); using (WebResponse response = await request.GetResponseAsync()) { using (Stream responseStream = response.GetResponseStream()) { using (StreamReader reader = new StreamReader(responseStream)) { string responseFromServer = reader.ReadToEnd(); token = JsonConvert.DeserializeObject<SpotifyToken>(responseFromServer); } } } } return token.access_token; } 

But I get an error message:

Der Remoteserver hat einen Fehler zurückgegeben: (400) Ungültige Anforderung.

What does it mean:

The remote server returned an error: (400) Bad request.

What am I doing wrong here? I registered my application to determine and set the clientId and secret in the request header ...

Thank you in advance

Answer 1

Do you really need to write your own client from scratch, creating WebRequests, etc.? Why not use an existing client like SpotifyAPI-NET ?

Anyway, you can see how they do it on GitHub:

https://github.com/JohnnyCrazy/SpotifyAPI-NET/blob/master/SpotifyAPI/Web/Auth/AutorizationCodeAuth.cs

 using Newtonsoft.Json; using SpotifyAPI.Web.Enums; using SpotifyAPI.Web.Models; using System; using System.Collections.Specialized; using System.Diagnostics; using System.IO; using System.Net; using System.Text; using System.Threading; namespace SpotifyAPI.Web.Auth { public class AutorizationCodeAuth { public delegate void OnResponseReceived(AutorizationCodeAuthResponse response); private SimpleHttpServer _httpServer; private Thread _httpThread; public String ClientId { get; set; } public String RedirectUri { get; set; } public String State { get; set; } public Scope Scope { get; set; } public Boolean ShowDialog { get; set; } /// <summary> /// Will be fired once the user authenticated /// </summary> public event OnResponseReceived OnResponseReceivedEvent; /// <summary> /// Start the auth process (Make sure the internal HTTP-Server ist started) /// </summary> public void DoAuth() { String uri = GetUri(); Process.Start(uri); } /// <summary> /// Refreshes auth by providing the clientsecret (Don't use this if you're on a client) /// </summary> /// <param name="refreshToken">The refresh-token of the earlier gathered token</param> /// <param name="clientSecret">Your Client-Secret, don't provide it if this is running on a client!</param> public Token RefreshToken(string refreshToken, string clientSecret) { using (WebClient wc = new WebClient()) { wc.Proxy = null; wc.Headers.Add("Authorization", "Basic " + Convert.ToBase64String(Encoding.UTF8.GetBytes(ClientId + ":" + clientSecret))); NameValueCollection col = new NameValueCollection { {"grant_type", "refresh_token"}, {"refresh_token", refreshToken} }; String response; try { byte[] data = wc.UploadValues("https://accounts.spotify.com/api/token", "POST", col); response = Encoding.UTF8.GetString(data); } catch (WebException e) { using (StreamReader reader = new StreamReader(e.Response.GetResponseStream())) { response = reader.ReadToEnd(); } } return JsonConvert.DeserializeObject<Token>(response); } } private String GetUri() { StringBuilder builder = new StringBuilder("https://accounts.spotify.com/authorize/?"); builder.Append("client_id=" + ClientId); builder.Append("&response_type=code"); builder.Append("&redirect_uri=" + RedirectUri); builder.Append("&state=" + State); builder.Append("&scope=" + Scope.GetStringAttribute(" ")); builder.Append("&show_dialog=" + ShowDialog); return builder.ToString(); } /// <summary> /// Start the internal HTTP-Server /// </summary> public void StartHttpServer(int port = 80) { _httpServer = new SimpleHttpServer(port, AuthType.Authorization); _httpServer.OnAuth += HttpServerOnOnAuth; _httpThread = new Thread(_httpServer.Listen); _httpThread.Start(); } private void HttpServerOnOnAuth(AuthEventArgs e) { OnResponseReceivedEvent?.Invoke(new AutorizationCodeAuthResponse() { Code = e.Code, State = e.State, Error = e.Error }); } /// <summary> /// This will stop the internal HTTP-Server (Should be called after you got the Token) /// </summary> public void StopHttpServer() { _httpServer = null; } /// <summary> /// Exchange a code for a Token (Don't use this if you're on a client) /// </summary> /// <param name="code">The gathered code from the response</param> /// <param name="clientSecret">Your Client-Secret, don't provide it if this is running on a client!</param> /// <returns></returns> public Token ExchangeAuthCode(String code, String clientSecret) { using (WebClient wc = new WebClient()) { wc.Proxy = null; NameValueCollection col = new NameValueCollection { {"grant_type", "authorization_code"}, {"code", code}, {"redirect_uri", RedirectUri}, {"client_id", ClientId}, {"client_secret", clientSecret} }; String response; try { byte[] data = wc.UploadValues("https://accounts.spotify.com/api/token", "POST", col); response = Encoding.UTF8.GetString(data); } catch (WebException e) { using (StreamReader reader = new StreamReader(e.Response.GetResponseStream())) { response = reader.ReadToEnd(); } } return JsonConvert.DeserializeObject<Token>(response); } } } public struct AutorizationCodeAuthResponse { public String Code { get; set; } public String State { get; set; } public String Error { get; set; } } } 

Answer 2

Spotify API from C #

 public string GetAccessToken() { SpotifyToken token = new SpotifyToken(); string url5 = "https://accounts.spotify.com/api/token"; var clientid = "your_client_id"; var clientsecret = "your_client_secret"; //request to get the access token var encode_clientid_clientsecret = Convert.ToBase64String(Encoding.UTF8.GetBytes(string.Format("{0}:{1}", clientid, clientsecret))); HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(url5); webRequest.Method = "POST"; webRequest.ContentType = "application/x-www-form-urlencoded"; webRequest.Accept = "application/json"; webRequest.Headers.Add("Authorization: Basic " + encode_clientid_clientsecret); var request = ("grant_type=client_credentials"); byte[] req_bytes = Encoding.ASCII.GetBytes(request); webRequest.ContentLength = req_bytes.Length; Stream strm = webRequest.GetRequestStream(); strm.Write(req_bytes, 0, req_bytes.Length); strm.Close(); HttpWebResponse resp = (HttpWebResponse)webRequest.GetResponse(); String json = ""; using (Stream respStr = resp.GetResponseStream()) { using (StreamReader rdr = new StreamReader(respStr, Encoding.UTF8)) { //should get back a string i can then turn to json and parse for accesstoken json = rdr.ReadToEnd(); rdr.Close(); } } return token.access_token; } 

Answer 3

Just code the App ClientId and ClientSecret:

 var token = Convert.ToBase64String(Encoding.UTF8.GetBytes(string.Format("{0}:{1}",this.CliendId,this.ClientSecret))); 

Correctly replace:

 request.Headers.Add("Authorization", "Basic " + token); 

What is it!