when do you need .ascx files and how would you use them?

Question

When building a website, when would it be a good idea to use .ascx files? What exactly is the .ascx and what is it used for? Examples would help a lot thanks!

Answer 1

Ascx-files are called User Controls and are meant for reusability and also for making complex aspx-pages less complex (lift out some part of the page). They could also be beneficial for something called donut caching, that is when you would like to cache a certain part of a page.