Directory.GetFiles

What files are in a specific folder? The Directory.GetFiles function answers this question—it will return an array of all paths in a folder.

Meanwhile, Directory.EnumerateFiles will do the same thing as Directory.GetFiles, but will not place them in an array. Instead it just returns the paths one at a time.

GetFiles example

The simplest way to get an array of the files in a location is with Directory.GetFiles with 1 argument. We must pass it the folder path.

imports System.IO

Module Module1
    Sub Main()
        ' Part 1: get files in relative directory.
        Dim array1 = Directory.GetFiles("programs/")
        Console.WriteLine("--- Files: ---")
        For Each name in array1
            Console.WriteLine(name)
        Next

        ' Part 2: filter files.
        Dim array2 = Directory.GetFiles("programs/", "*.TXT")
        Console.WriteLine("--- TXT Files: ---")
        For Each name in array2
            Console.WriteLine(name)
        Next
    End Sub
End Module
--- Files: ---
programs/spellbug
...
--- TXT Files: ---
programs/search-perls.txt
programs/example.txt
programs/words.txt

List

It is possible to place the array returned by GetFiles() into a List. We can use the ToList function to get a List from the array.

imports System.IO

Module Module1
    Sub Main()
        ' Get array for absolute directory.
        Dim array = Directory.GetFiles("/Users/Sam/programs/")

        ' Convert to list.
        Dim filesList = array.ToList()
        Console.WriteLine(filesList.Count)
    End Sub
End Module
21

AllDirectories

Sometimes we want to recursively open folders, and then add files from those directories into the result. This can be done with SearchOption.AllDirectories.

imports System.IO

Module Module1
    Sub Main()
        ' Use AllDirectories option to recursively traverse folders.
        For Each file in Directory.EnumerateFiles("programs/", "*.*", SearchOption.AllDirectories)
            Console.WriteLine("IN DIRECTORY: " + file)
        Next
    End Sub
End Module
IN DIRECTORY: programs/rewrite.go
...
IN DIRECTORY: programs/vbtest/Program.vb

With Directory.GetFiles and EnumerateFiles, we access the file paths within a folder. We can specify a filter string, or even handle nested directories with SearchOption.