Get Sharepoint Current Logged in UserName in ASP.NET web application Page View Webpart

Get Sharepoint Current Logged in UserName in ASP.NET web application displayed in PageView Web Part -

HttpContext.Current.User.Identity.Name;

Note: Make sure in IIS your web application has ASP.NET Impersonation
and Windows Authentication Turned On. All all other option turned off.
Take a look at screen shot.

Screenshot – IIS Settings

IIS Settings - Authentication

IIS Settings - Options