ASP MVC best practice for getting current username in UnitOfWork data access layer?

Question

ASP MVC best practice for getting current username in UnitOfWork data access layer?

I can not retrieve the authenticated user in UI APP in UnitOfWork class, please invaluable assistance

public override int SaveChanges()
{
    var changeSet = ChangeTracker.Entries<IAuditoria>();

    if (changeSet != null)
    {
        string username = "Dafault";
        DateTime dateAudit = DateTime.UtcNow;
        foreach (var entry in changeSet.Where(c => c.State != EntityState.Unchanged))
        {
            if (entry.State.Equals(EntityState.Added))
            {
                entry.Entity.UsuarioCreacion = username;
                entry.Entity.FechaCreacion = dateAudit;
            }
            entry.Entity.GuidAuditoria = Guid.NewGuid().ToString();
            entry.Entity.FechaActualizacion = dateAudit;
            entry.Entity.UsuarioActualizacion = username;//"HttpContext.Current.User.Identity.Name"
        }
    }

    return base.SaveChanges();
}