ASP.NET (OWIN) Identity: How to get UserID from a Web API controller?

Question

(Using VS2013 RTW, ASP.NET MVC5)

I\'ve seen lots of documentation on how to add properties to the ApplicationUser class (and table) when using ASP.NET identity. But

Answer 1

Tried @Mastenka answer and it gave me nothing. I checked ClaimsIdentity and there were claims type "UserName", so as a result, I get username by using "UserName" as ClaimsType. Hope someone will give more info about it. It looks strange that "ClaimTypes.NameIdentifier" had no effect. (ApiController, ASP MVC API)

var userName = ((ClaimsIdentity)RequestContext.Principal.Identity).Claims.FirstOrDefault(cl => cl.Type == "UserName")?.Value;