Aug 14, 2019 07:39 PM|Mikesdotnetting|LINK
Why don't you want to use PageModel properties or tag helpers? If you want to continue to use Request["..."], you might as well not use Razor Pages at all.
But if you are set on going that route, you could try Request.Query["hdfSearchType"].ToString()
If it's a form field rather than a query string value, you will have more hoops to jump through. A PageModel property is the simplest option.