I have couple of questions in this regard

1)If I have developed a user control (say for example Login User control).
Can I use it in various other web-applications by placing login user control
source code in App_code folder of some other web application in which I
want to make use of it?.

2) If I have compiled a user control in to an assembly. and in another
web application can I register this user control using @register directive
and use it?

3) If reusability of user control across web Apps is possible, is it a good
idea to use it across web applications?

Thanks in Advance,