Get all the folders and sub-folders in side a directory

Question

I am learning VB.net, I would like to know how to get all the folders and sub-folder s inside a directory and how to add them all to a listbox. I would also like it to list the folders while it is scanning like showing the current folders found. I have tried a few things but they never seem to work. I have tried this:

Sub GetDirectories(ByVal StartPath As String, ByRef DirectoryList As ArrayList)
    Dim Dirs() As String = Directory.GetDirectories(StartPath)
    DirectoryList.AddRange(Dirs)
    For Each Dir As String In Dirs
        GetDirectories(Dir, DirectoryList)
    Next
    For Each item In DirectoryList
        ListBox1.Items.Add(item)
    Next
End Sub

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    Dim DirList As New ArrayList
    GetDirectories("c:\hexing\", DirList)
End Sub

Answer 1

Try this

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Try
    Dim DirList As New ArrayList
    Dim Dirs() As String = Directory.GetDirectories(StartPath)
    DirList.AddRange(Dirs)
    For Each Dir As String In Dirs
        GetDirectories(Dir, DirectoryList)
    Next
    Catch ex As Exception
End Try
End Sub

(Or)

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        For Each Dir As String In Directory.GetDirectories("c:\Program Files")
            ListBox1.Items.Add(Dir)
        Next
End Sub

Edit

According to VB.NET 05, List Folder, SubFolders, and Sub SubFolders:

The most efficient way would be to use recursivity:

 Private Function getAllFolders(ByVal directory As String) As String()
        'Create object
        Dim fi As New IO.DirectoryInfo(directory)
        'Array to store paths
        Dim path() As String = {}
        'Loop through subfolders
        For Each subfolder As IO.DirectoryInfo In fi.GetDirectories()
            'Add this folders name
            Array.Resize(path, path.Length + 1)
            path(path.Length - 1) = subfolder.FullName
            'Recall function with each subdirectory
            For Each s As String In getAllFolders(subfolder.FullName)
                Array.Resize(path, path.Length + 1)
                path(path.Length - 1) = s
            Next
        Next
        Return path
 End Function