如何替换。net Core View类的Request.Url.GetLeftPart(uripartitional . authority) ?

I am trying to migrate few View classes into .NET Core from .NET and I am having an issue with the lack of "Request" class methods. The following question might be related to my situation but I wasn't sure how to use UriBuilder or any of the other answer for this purpose. I wanted to ask something more specific and a little different. I am trying to migrate few View classes into .N