Including subdirectories?

I have this code that searches a directory:

Code:

---

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        ' make a reference to a directory
        Dim di As New IO.DirectoryInfo("c:\")
        Dim diar1 As IO.FileInfo() = di.GetFiles()
        Dim dra As IO.FileInfo

        'list the names of all files in the specified directory
        For Each dra In diar1
            ListBox1.Items.Add(dra)
        Next
    End Sub

---

How do I make it so that it includs subdirectories?

Create a function to search through subdirectories and then call that recursivly to search each subdirectory's subdirectories. Something like this.....

Code:

---

Private Sub Button1_Click(ByVal sender As System.Object, _
    ByVal e As System.EventArgs) Handles Button1.Click

    Dim rf As New System.IO.DirectoryInfo("d:\VBNET")
    Dim file As System.IO.FileInfo
    For Each file In rf.GetFiles
        ListBox1.Items.Add(file.FullName)
    Next
    getsubdirs(rf)

End Sub

Sub getsubdirs(ByVal rf As System.IO.DirectoryInfo)

    Dim sfolders() As System.IO.DirectoryInfo = rf.GetDirectories
    Dim folder As System.IO.DirectoryInfo
    For Each folder In sfolders
        getsubdirs(folder)
        Dim file As System.IO.FileInfo
        For Each file In folder.GetFiles
            ListBox1.Items.Add(file.FullName)
        Next
    Next

End Sub

---