Box API always returns invalid grant_type parameter on obtaining access token

Question

I\'m writing my own Box SDK for WP8 to make the most out of Tasks. I am having trouble obtaining an access token. I always get this as a return:

{\"error\":\         


        

Answer 1

in Windows phone 8.1 WinRT

Dictionary contentList = new Dictionary();

contentList.Add("code", code);
contentList.Add("client_id", client_id);
contentList.Add("client_secret", clientSecret);
contentList.Add("redirect_uri", redirectUri);
contentList.Add("grant_type", "authorization_code");

FormUrlEncodedContent content = new FormUrlEncodedContent(contentList);

var response = await client.PostAsync(baseURL, content);
YouTubeAutenticationResponse res =       JsonConvert.DeserializeObject(await     response.Content.ReadAsStringAsync());

public class YouTubeAutenticationResponse
{
    [JsonProperty("access_token")]
    public string AccessToken { get; set; }
    [JsonProperty("token_type")]
    public string TokenType { get; set; }
    [JsonProperty("expires_in")]
    public string ExpiresIn { get; set; }
    [JsonProperty("refresh_token")]
    public string RefreshToken { get; set; }
}