Question

How do I do System.IO.Directory.GetFiles("*.tif") and System.IO.Directory.GetFiles("*.jpg") in the same call?

Answer 1

The most efficient way I believe (scanning the directory only once, and yielding results without first building up the whole list) is like this:

var extensions = new[] {".jpg", ".tif"};
var files = from f in Directory.EnumerateFiles(folderPath)
            where extensions.Contains(Path.GetExtension(f))
            select f;

Of course, if you need to loop over the results more than once it’s probably best to store the result in a list anyway.