Question

Good morning,

is there a way to get a DriveInfo instance for UNC paths (e.g. ‘\fors343a.ww123.somedomain.net\folder\1\’) because for example…

var driveInfo = new System.IO.DriveInfo(drive); 

… throws an ArgumentException (‘Object must be a root directory (\’C:\\’) or a drive letter (\’C\’).’) when using that UNC path above.

What would I use in order to retrieve information about that or e.g. how would I check whether a given folder resides on a local drive or an unc path?

Answer 1

The Remarks section for the DriveInfo constructor says:

The drive name must be either an uppercase or lowercase letter from ‘a’ to ‘z’. You cannot use this method to obtain information on drive names that are nullNothingnullptra null reference (Nothing in Visual Basic) or use UNC (\server\share) paths.

I was able to make it work by mapping a network drive in Windows Explorer. That is, I mapped ‘\server\share’ to drive Z, and then DriveInfo('Z:\\'); gave me what I expected.

Unfortunately, there’s no simple way to map a network drive from C#. You’ll either have to execute an external command (i.e. ‘net use z: \server\share’), or call the Windows WNetAddConnection2 API function to do it. Either way you go, you’ll need to remove the drive mapping when you’re done.