How to get the list of all directories and subdirectories in a specified path using vb.net

Question

My directory structure is like below.

Parent directory
---Sub directory 1 ---Sub directory 2 ------Sub directory2a ------Sub directory2b ---Sub directory 3

Answer 1

Dim di As New DirectoryInfo(FolderName)
di = New DirectoryInfo(path)

rgFiles = di.GetFiles("*.*", IO.SearchOption.AllDirectories)

For Each fi As FileInfo In rgFiles
    If CheckIfExist(fi.FullName.ToString.Replace("\" & fi.Name, "")) = False Then
        ListBox1.Items.Add(fi.FullName.ToString.Replace("\" & fi.Name, ""))
    End If
Next

Public Function CheckIfExist(ByRef Path As String) As Boolean
    Dim RetVal As Boolean = False

    For Each LI As String In ListBox1.Items
        If LI.ToString = Path Then
            RetVal = True
            Return RetVal
            Exit Function
        End If
    Next
    Return RetVal
End Function