Get values from the source code(aspx.vb)

I have a page with page_load function to get the user id 
  
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Dim user As MembershipUser = Membership.GetUser
Dim UserID As String = user.ProviderUserKey.ToString
End Sub In my aspx page, I would like to use the userid for my sql query in gridviews.
I know I can use Session, but I do not want to use it as I think it may consume more server memory.
Any advices?
Thank you.

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