ASP.NET Reflection problem

  • Thread starter Thread starter Guest
  • Start date Start date
G

Guest

Hello,

I have an asp.net web page (say page.aspx) which derives from a custom base
page object (CustomPage : BasePage : System.Web.UI.Page) Which has a method
called DoSomething(params). My web page contains a UserControl (say
Control.ascx).

In the control class, i want to call the DoSomething method. I cannot use
type cast since in fact the base class Page structure is a little more
complex (see bottom of post). Hence i cannot do:
CType(Me.Page, BasePage).DoSomething(params)

instead i use reflection

Me.Page.GetType().InvokeMember("DoSomething", BindingFlags.InvokeMethod,_
Nothing, Me.Page, New Object() {param})
'This is pretty much the same type of code used to call methods from a
master
'page in a UserControl (since master page's data type in not accessible
from a
'usercontrol)

In any .NET App or Web app, this works well. But for some reason, it doesn't
work in a UserControl. (This code works fine in the aspx code behind but not
in the ascx code behind).

In a UserControl's code behind, this throws a MissingMethodException

Anyone already experienced this issue?

What is very strange here is that the following code does work

Dim mi As Reflection.MethodInfo = Me.Page.GetType().GetMethod("DoSomething")
mi.Invoke(Me.Page, Reflection.BindingFlags.InvokeMethod, Nothing, New
Object() {param}, Nothing)

Thanks

Renaud

==============================
Base Class Page structure

Class FoundationBasePage : System.Web.UI.Page
Class FoundationBaseFirstPage : FoundationBasePage
Class FoundationBaseLastPage : FoundationBasePage

Class BasePage : FoundationBasePage
Class BaseFirstPage : FoundationBaseFirstPage
Class BaseLastPage : FoundationBaseLastPage

The method DoSomething is located in BasePage, BaseFirstPage and BaseLastPage
The UserControl may be used in pages inheriting from any of those three base
classes.
 
the methods needs to be public. a better approach is for the page to
implement an interface, then the user control can cast the Page to the
interface, and call the method directly, rather than use reflection.

-- bruce (sqlwork.com)
 
Thanks for your reply. I feel a bit stupid that i didn't think about the
interface...

Yet, it should work. The function i am calling is public (it works when
called from the aspx code behind).

I already solved the problem using the GetMethod call (exposed later in my
previous post) but i think designing an interface is more neat and is
probably faster.

Thanks a lot

Renaud
 

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