c# - do interfaces belong in files of their own -

As a rule of thumb I usually put classes in my files. Visual Studio encourages it, but what is proper regarding the interface?

For example

I have a class FU which implements the interface bar

  Public Interface IBR {} Public Class Fu: IBR {}

It seems that it implements the interface to a group within the same file, but it takes more than 2 lines to dedicate a file, but correct.

What's appropriate?

I will split them into 2 files.

Trying to find Class Fu in a file named Icar.cs or vice versa.

/ html>

Dos2Unix