Private Function GetFiles(ByVal di As DirectoryInfo, ByVal searchMask As _
      String) As FileInfo()
        Dim masks() As String = Split(searchMask, ";")
        Dim files As New ArrayList
        For Each mask As String In masks
            For Each fi As FileInfo In di.GetFiles(mask.Trim())
                files.Add(fi)
            Next
        Next
        Return files.ToArray(GetType(FileInfo))
    End Function

        For Each file As FileInfo In GetFiles(di, "*.dll; *.exe")
            ListBox2.Items.Add(file.Name)
        Next