How to Show or hide controls based on roles – ASP.NET MVC 4 Razor

I m working on ASP.NET MVC 4 application.I have a dashboard and my users groups will be based on Windows Domain
So I am using WIndows Authentication for authenticating users.
I created sample applications which uses custom authentication by overrides functions AuthorizeAttribute, ActionFilterAttribute . Is this a good approach ?

ActiveDirectory Current Username in ASP.NET

I’m trying to get both ActiveDirectory and standard forms login working but one thing is stopping me. I can’t get the name of the current windows user. The closest I’ve got is var i = WindowsIdentity.GetCurrent();, but that gives me the name of the IIS app pool user. I have Anonymous Authentication, Forms Authentication and Windows Authentication enabled in IIS. I can load users from AD so I assume my web.config is setup correctly.