Question

Hi i’m developing an application in facebook with c# sdk and i want that the user whom liked my page can only use my application. (Like woobox)

I found some solutions in php in this link but there isn’t any source about .net how can i get the liked info in ASP.NET

I find another examples in php in this link again but i can’t find c# answer :\

Thanks

Answer 1

You get signed request when your web page is loaded within facebook canvas app; you should be able to parse signed request something similar to following:

if (Request.Params["signed_request"] != null)
{
    string payload = Request.Params["signed_request"].Split('.')[1];
    var encoding = new UTF8Encoding();
    var decodedJson = payload.Replace("=", string.Empty).Replace('-', '+').Replace('_', '/');
    var base64JsonArray = Convert.FromBase64String(decodedJson.PadRight(decodedJson.Length + (4 - decodedJson.Length % 4) % 4, '='));
    var json = encoding.GetString(base64JsonArray);
    var o = JObject.Parse(json);
    var lPid = Convert.ToString(o.SelectToken("page.id")).Replace("\"", "");
    var lLiked = Convert.ToString(o.SelectToken("page.liked")).Replace("\"", "");
    var lUserId= Convert.ToString(o.SelectToken("user_id")).Replace("\"", "");
}

You need to add reference to json libraries in order to parse signed requestin C#, download from http://json.codeplex.com/

Also refere to How to decode OAuth 2.0 for Canvas signed_request in C#? if you are worndering about signed request.