Generar keys aleatorias

[Jnl]

Pues algo asi con substring y un rand

Código vb:

Public Function randText(lenght As Integer) As String
    Dim r As New Random()
    Dim str As String = ""
    Dim rand As String = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
    For i As Integer = 0 To lenght - 1
 
        str += rand.Substring(r.[Next](62), 1)
    Next
    Return str
End Function