CodeFile or CodeBehind
Date Published: 24 January 2007
I just fixed a problem on a coworker’s machine that was quite odd in that the fix involved simply changing CodeFile to CodeBehind in a user control (.ascx) file. The issue was that in the ASPX page I was doing a FindControl within a Repeater’s ItemDataBound event, and casting the resulting control to the type of the codebehind of the user control. So for example if the user control was foo.ascx then in foo.ascx.cs I might have had a type Acme.Web.Foo. The Inherits= attribute in the @Control directive was set correctly to Acme.Web.Foo, but the type cast was failing in the ASPX page. When I debugged it, I found that the type of the thing I was getting back from FindControl was the JIT compiled ASCX’s type, which was ASP.Folder_Foo_ascx. The strange thing was that this was uncastable to its base class, Acme.Web.Foo, as long as the ASCX contained CodeFile=”foo.ascx.cs”. I changed this to CodeBehind=”foo.ascx.cs” and suddenly everything worked.
I think this is related to my upgrade from a website to a Web Application Project, described in a post yesterday. I don’t have time at the moment to investigate why the inheritance tree for my ASCX page would be broken by this change, but if anybody would care to comment I certainly interested.
Incidentally, this is my first post with the new BlogJet 2.0. So far it looks much nicer than the previous version, although it hasn’t actually posted as I’m typing this…
Steve is an experienced software architect and trainer, focusing on code quality and Domain-Driven Design with .NET.