public AuthenticationToken CurrentAuthenticationToken() { String authenticationTokenString = IOSWrapper.IOSFBCurrentAuthenticationToken(); if (String.IsNullOrEmpty(authenticationTokenString)) { return(null); } try { IDictionary <string, string> token = Utilities.ParseStringDictionaryFromString(authenticationTokenString); string tokenString; string nonce; token.TryGetValue("auth_token_string", out tokenString); token.TryGetValue("auth_nonce", out nonce); return(new AuthenticationToken(tokenString, nonce)); } catch (Exception) { return(null); } }