get UniqueRandomNumbers

gistfile1.cs

        Private Shared Function UniqueRandomNumbers(NumAleatories As Integer, elements As Integer) As List(Of Integer)

            Dim aleatorios As New List(Of Integer)

            If elements > 0 Then
                Dim temp As List(Of Integer) = Enumerable.Range(0, elements)
                If NumAleatories > elements Then
                    aleatorios = temp.OrderBy(Function(a) Guid.NewGuid())
                Else
                    Dim r As New Random(DateTime.Now.Millisecond)

                    For i As Integer = 0 To NumAleatories - 1
                        Dim start As Integer = r.Next(0, temp.Count - 1)
                        aleatorios.Add(temp(start))
                        temp.RemoveAt(start)
                    Next
                End If
            End If

            Return aleatorios

        End Function