Examples of SOLID Principles in ASP.Net C # Web Form

I study SOLID principles and find many articles with business classes as an example.

SOLID's principles are to separate classes in which ASP.NET (event-based ASP.NET web form development) encodes web forms that are closely related to controls. Therefore, I would like to see practical examples of SOLID principles in web form code behind files.

Please note that I do not want MVC.

Links to sites / books that are explained in detail will also help.

Thanks in advance.