Are you sure you understand the difference between CodeFile and CodeBehind? See, for example, CodeFile vs CodeBehind (ignore the accept answer, although both links are dea) or this article on the difference.
In a nutshell:
Assuming fileA CodeBehind , bin -. ASP.NET aspx, Inherits, . CodeBehind ( , , " " ), .
CodeFile ASP.NET , . " " -, , , -. CodeFile .cs, , ASP.NET. ( : CodeFile - partial class, , #, CodeFile , # .)
CodeFile CodeBehind, ASP.NET # . ASP.NET, , , , .