I need to let user loading file from my asp site

Good day
 
I have asp site using sql db and c#
 
I need to let site visitors loading file from the site as (pdf,doc,..) the files are in sub folders in the site folder , the files link are in the sql DB .
I use DetailsView control to displaying search   result from data set including the files path.
 
What the way to loading file from details View, is it (button field or link field )
and what's the field code ??.