Content Page Accessing Event Handlers from Two Different Master Pages

[bmiller]

I have a ASP.NET content page where the master page is set dynamically. Both master pages contain a print button and an associated event handler for the click event of the button. Unfortunately I receive a run-time error when I attempt to dynamically access the event from the master page that was not initially assigned.

Below are code snippets:

Page_Load():
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Dim strPageTitle As String = "Evaluator Data Form - Instructions"

If Page.MasterPageFile.Contains("masEvaluators.master") Then
Dim mp As Evaluators_masEvaluators = CType(Me.Master, Evaluators_masEvaluators)
AddHandler mp.SaveEDF, AddressOf imgbtnPrint_Click

ElseIf Page.MasterPageFile.Contains("masStaff.master") Then
Dim mp As Staff_maStaff = CType(Me.Master, Staff_maStaff)
CType(Page.Master.FindControl("imgbtnPrint"), ImageButton).Visible = True

AddHandler mp.SaveEDF, AddressOf imgbtnPrint_Click
End If

which produces the following error when I load the page and reference the "masStaff.master" master page:

System.InvalidCastException: Unable to cast object of type 'ASP.staff_masstaff_master' to type 'Evaluators_masEvaluators'. at Evaluators_EDF_Instructions.Page_Load....

I can solve the problem by adding a print button to the content page, but that defeats the purpose of using a master page.

Is there a solution to this problem? I have spent many hours researching this issue on the web, but have not found a solution as of yet.

Thanks!

[brin351]

I'm not on my dev machine so can't check/give some code that I think addresses this but from memory the solution is.

1. create a base class that derives from master page that your 2 master pages inherit from.
2. In that base class define your print method... ? > not certain how your wire up events will work but maybe this is a different approach.
3. In your @ page directives use <%@ MasterType TypeName="BaseMaster" %> so you refrence the master page by type not individual class as showen in the following msdn link.

http://msdn.microsoft.com/en-us/libr...v=vs.100).aspx

This should prevent the cast error because it's 1 class not 2

Hope that helps.