If you're going to check if a directory exists, you should use
System.IO.Directory.Exists()
function which returns
True
if the directory exists and
False
otherwise.
If you're going to check if a file exists, you should use
System.IO.File.Exists()
function.
If you want to iterate through all files in a directory, you should use
System.IO.Directory.GetFiles(string path)
Check
Microsoft's documentation on System.IO.Directory