Get current logged in username from Active Directory? - asp.net

Question

My web application uses Active Directory Authentication when a user logs in. I use the following code for audit columns. It works perfectly fine for the CreatedAt and ModifiedAt dates but the currentUsername is hardcoded.
public override int SaveChanges()
{
var entities = ChangeTracker.Entries().Where(x => x.Entity is BaseClass && (x.State == EntityState.Added || x.State == EntityState.Modified));
var currentUsername = "T";
foreach (var entity in entities)
{
if (entity.State == EntityState.Added)
{
((BaseClass)entity.Entity).CreatedAt = DateTime.Now;
((BaseClass)entity.Entity).CreatedBy = currentUsername;
}
((BaseClass)entity.Entity).ModifiedAt = DateTime.Now;
((BaseClass)entity.Entity).ModifiedBy = currentUsername;
}
return base.SaveChanges();
}
How can I get the current username logged in Active Directory?

Answer 1

If you're on .NET 4.5 or higher, just use the System.DirectoryServices.AccountManagement namespace and the UserPrincipal class in that context:
// you'll need to add a reference to this .NET assembly in your project
// so that you can use this namespace
using System.DirectoryServices.AccountManagement;
public string GetLoggedInUser()
{
// establish the PrincipalContext - this will grab the default domain, default containers
using (PrincipalContext ctx = new PrincipalContext(ContextType.Domain))
{
// get the currently active user
UserPrincipal currentUser = UserPrincipal.Current;
if (currentUser != null)
{
// this will return "first name last name" separated by a space,
// e.g. "John Doe" or "Jane Tarzan"
return $"{currentUser.GivenName} {currentUser.Surname}";
}
}
return string.Empty;
}