How to understand whether the visitor is Googlebot or not ? ASP.net

Question

How to understand whether the visitor is Googlebot or not ? ASP.net 4.0 & C#

I mean i want to understand that if the visitor is Googlebot or not.

Answer 1

if (Request.UserAgent.IndexOf("Googlebot") != -1)
{
  // google!
}

I think, according to the headers supplied by this website

Answer 2

You need to check the request headers

Each time something requests your website it gives up some information itself, as per @Brads answer you're checking whether whatever is requesting your site is calling itself 'Googlebot'. Of course this can be a lie - so you can't place any great trust within this value.