Hello
I took some code from an example and implemented it but I not sure why it works.

The sample code has <%@ Page Language="vb" Explicit="True" Debug="True" %> and no Inherits or Codebehind attributes.

When I added the appropriate Inherits & Codebehind attribute it doesn't run. But when I leave it as <%@ Page Language="vb" Explicit="True" Debug="True" %> it works.

Why does this work????????

Is it because the sample code has been compiled already and doesn't need Inherits & Codebehind?

I thought these two were required for the ASPX page to run???

The two aren't required; remember that ASP.NET doesn't require a code-behind page; Visual Studio .NET just happens to use that compilation model.

As Brian stated, the "CodeBehind" attribute of the directive is essentially meaningless to ASP.NET. It's strictly a helper for Visual Studio.

The "Inherits" attribute however is significant. When ASP.NET parses the .aspx file, it dynamically compiles a new class for that page: "mypage_aspx". By default, that class is inherited from System.Web.UI.Page. The inherits statement tells the compiler to inherit from the codebehind class. So if you tried to inherit from a class that doesn't exist, you'll get an error. As long as this class exists in an assembly that is "searchable" (i.e. it's in the local application /bin or the framework location or the global assembly cache) than the page should run.