Question

I’ve got two aspx pages which are very similar and have various identical functions in the code behind. I’d like to create a base class which both the code behind classes derive from. Is it possible for the base class to access the controls on the aspx page. For instance:

class base
    inherits System.Web.UI.Page
    Sub prepareScreen()
       'txtName is a text box on the aspx page
       Me.txtName.text = "George"
    end sub
end class

class codeBehind
     inherits base
     Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
          prepareScreen()
     end sub
end class

Somewhat understandably the code fails to compile with:

'txtName' is not a member of 'clsbase'

Is it possible to link the two together?

Answer 1

You need to declare the control as a property of the base class. Then in the ASP markup, use the CodeFileBaseClass attribute.

The MSDN reference is no longer available.

class base
    inherits System.Web.UI.Page
    Protected Property txtName() As TextBox
    Sub prepareScreen()
       'txtName is a text box on the aspx page
       Me.txtName.text = "George"
    end sub
end class

class codeBehind
     inherits base
     Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
          prepareScreen()
     end sub
end class

<%@ page CodeFileBaseClass="base" inherits="codebehind" ...  %>