Public Function GetFiles(ByVal path As String, ByVal Pattern As String, ByRef _
  arr As ArrayList)
        arr.AddRange(IO.Directory.GetFiles(path, Pattern))
        Dim s As String
        For Each s In IO.Directory.GetDirectories(path)
            GetFiles(s, Pattern, arr)
        Next
        Return arr
    End Function

Public Sub Search()
        Dim sr As IO.StreamReader
        Dim fw As New StreamWriter(_textSearch, True)
        Dim s As String
        Dim r As System.Text.RegularExpressions.Regex
        Dim searchWord As String
        Dim matches As Integer
        For q = 0 To typeArray.Count - 1
            Dim arr As New ArrayList()
            GetFiles(_folder, typeArray.Item(q), arr)
            Dim f As String
            For Each f In arr
               Try
                    sr = New IO.StreamReader(f)
                    s = sr.ReadToEnd 
                    sr.Close()
                    searchWord = "http"
                    r = New System.Text.RegularExpressions.Regex(searchWord)
                    matches = r.Matches(s).Count
                    If matches > 0 Then
                        fw.WriteLine(f + " - Treffer: " + matches.ToString)
                    End If
                    s = String.Empty
                Catch ex As Exception
                    fw.WriteLine("folgender Fehler beim Einlesen der Datei " & _
                      f _
                      & ": " & ex.Message)
                End Try
                            Next
            If matches = 0 Then
                fw.WriteLine("nichts gefunden")
            End If
                 Next
    End Sub