Question

• Is it possible to generate barcode from a string
  using c#?
• Is there any builtin classes for generating barcodes in asp.net?
• Is it possible to detect a barcode printer connected with a system?

Answer 1

Yep. Of course it is possible. 🙂
As far as I know there are two ways to generate bar codes:

1. Using a special bar code font (try to google for "barcode font free")
2. Render the bar code to an image and display that (try using the Barcode Rendering Framework available on github)

In response to your updated question about detecting barcode printers:
I think a barcode printer will show up as a regular printer on your system. At least that is how the devices I have played with have worked.
This means that you can detect a specific barcode printer by enumerating the installed printers on the system and looking for the specified device, but in most cases I would suggest that you let the user specify the printer himself using either the standard print dialog or using a custom dialog.