Question

Im trying to get the Facebook users id saved in my database but I got this error:

System.NullReferenceException: Object reference not set to an instance of an object.

Im using Newtonsoft.Json.Linq and the method SelectToken to get the "registration.id"

Here is the code:

string FB_ID= o.SelectToken("registration.id").ToString();
string FB_Firstname = o.SelectToken("registration.first_name").ToString(); 
string FB_Lastname = o.SelectToken("registration.last_name").ToString();

I can successfully get the Firstname and Lastname of the user but the string FB_ID gives me the Object reference not set to an instance of an object error.

Answer 1

I do not know which FB library you are using (Facebook C# SDK does not have a SelectToken method)… but Facebook uses “uid” instead of “id”.

So… you might need to use:

string FB_ID= o.SelectToken("registration.uid").ToString();

Hope it helps.