Identity Framework, access to sign in user.

Hey, I have question, I configured default Identity in my web app in asp net.core 2.1, and I need details of current sign in user. How can do that???

 

In controller I can do : 
private readonly UserManager _userManager;

ApplicationUser x = await _userManager.GetUserAsync(User);

x.SomeFieldsOrMethods

 

but I need access to these fields in other .cs file where I have a SignalR Hub functions and there I haven't access to the 'User'. 

 

In other way I tried :

After each sign in I add two new claims 

 

 then in my Hub.cs file : 
var httpcontext = Context.GetHttpContext();  
string login = httpcontext.User.FindFirst("UserLogin").Value; <--this get a login well
string login = httpcontext.User.FindFirst("UserId").Value; <-- this get an UserId, but in string type, but iny my database I have integer Id. I tried parse to int in few ways but always failed. 

Please help me, how can I get user id (int) and other fields in other .cs files.

Thanks