windows phone 8 - Add track to playlist SoundCloud API

Question

In my Windows Phone App, I'm using the following code to add a track to playlist (i.e. a PUT request to playlists/id endpoint)

    using (HttpClient httpClient = new HttpClient())
            {
                httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue(AccessToken);
                HttpResponseMessage response = await httpClient.PutAsync(endpoint, new StringContent(data));
                response.EnsureSuccessStatusCode();
            }

where "data" is JSON data the form:

    {"playlist":{"tracks":["TrackId(to be added)"]}}

The above code returns "OK"(200) response but the track is NOT added to the playlist!

What am I doing wrong? Stuck on it for two days. Thanks in advance!

Answer 1

I use Put to replace track ids in set. here is sample code

for (String s : trackIds)
    nameValuePairs.add(new BasicNameValuePair("playlist[tracks][][id]", s.trim()));

String url = "https://api.soundcloud.com/playlists/" + setId + ".json";
httpPut(url, nameValuePairs);