''' <summary>
    ''' Ruft für jede Permutation der Elemente aus arr den angegebenen Delegat
    ''' auf.
    ''' </summary>
    ''' <typeparam name="T">der Typ des Arrays</typeparam>
    ''' <param name="arr">das Array</param>
    ''' <param name="act">Ein Delegat vom Typ Action(Of T()), der für
    ''' jede Permutation aufgerufen werden soll</param>
    ''' <remarks></remarks>
    Public Shared Sub ForEachPermutation(Of T)(arr As T(), _
            act As Action(Of T()))
        Dim newArray As T() = New T(arr.Length - 1) {}
        Dim indexes As Integer() = New Integer(arr.Length - 1) {}
        Dim taken As Boolean() = New Boolean(arr.Length - 1) {}
 
        ForEachPermutationRek(arr, act, indexes, taken, 0, newArray)
    End Sub
 
    Private Shared Sub ForEachPermutationRek(Of T)(arr As T(), act As Action(Of _
      T()), indexes As Integer(), taken As Boolean(), pos As Integer, newArray _
      As T())
        For i As Integer = 0 To arr.Length - 1
            ' Schauen, ob die POsition belegt is
            If Not taken(i) Then
                taken(i) = True
                indexes(pos) = i
                If pos < arr.Length - 1 Then 'rekursiv aufrufen
                    ForEachPermutationRek(arr, act, indexes, taken, pos + 1, _
                      newArray)
                Else
                    'neues Array füllen und die Action aufrufen
                    For j As Integer = 0 To arr.Length - 1
                        newArray(j) = arr(indexes(j))
                    Next
                    act.Invoke(newArray)
                End If
                taken(i) = False
            End If
        Next
    End Sub

    Dim arr As Integer() = {1, 2, 3}
 
    Dim ausgabeNr As Integer = 0
    ForEachPermutation(arr, _
        Sub(array As Integer())
            ausgabeNr += 1
            Debug.WriteLine("Permutation " & ausgabeNr & ": " & String.Join( _
              ",", array))
        End Sub)

Permutation 1: 1,2,3
Permutation 2: 1,3,2
Permutation 3: 2,1,3
Permutation 4: 2,3,1
Permutation 5: 3,1,2
Permutation 6: 3,2,1