URL Query String parsing

My URL is the following
http://localhost:62098/MyWebsite/ViewTraining.aspx?file.pdf
I want to retrieve only file.database from the query string in the URL

My code is below

 Dim FinalAbsoluteURL As String
            Dim  Parseme as string
            Dim MyUrl As String = Request.Url.AbsoluteUri
            Dim uri As New Uri(MyUrl)
            Dim Something As String = Path.GetFileName(uri.LocalPath)
            Dim Spliting As String() = MyUrl.Split("\"c)

            Dim lengths As Integer = Spliting.Length
...