When you inherit, you are not inheriting a file, but a class. You could have the following:
myproject/folder/folder/folder/folder/folder/folder/myclass.cs
with the class looking like this:
Public Class MyClass
End Class
When you want to inherit from this, the class name is still only "MyClass" regardless of where the physical code file lives. Therefore, you would still only inherit like this:
Public MyNewClass
Inherits MyClass (or MyProject.MyClass)
End Class
This applies to web pages as well. Your webform codebehind class is "WebForm" so the web page needs to inherit from that name only:
<%@ Page Language="
vb" AutoEventWireup="false" Codebehind="FolderName/Webform.aspx.
vb" Inherits="Projectname.Webform"%>
Specific paths matter when you are trying to reference a page or other resource in your web application, such as in a hyperlink or image.