I know that in Windows Form Application you can inherit a Form and in ASP.NET u can inherit a page but some big constraint exist: ASPX page is not compiled in the library.
I tried to embed a User Control in DLL but Design Time is not supported, also I tried to make a Custom Server Control but in the end you are inheriting a control not Page.
So the question is what is the way to make your own library of Template Pages that u can inherit and use in different projects with design support .
Thanks in advance