I made a Bingo game and use a randomly generated set of 75 ball numbers for each new game.
The array is public and is aryRnd(75). This works well for me and is reasonably fast.
You can then use the array as needed in the project.
Dim valueRnd As String = ""
Dim ballCnt As Single = 0
Dim gotcha As Boolean = False
Dim z As Single = 0
Dim Xy As Single
For Xy = 0 To 75
aryRnd(Xy) = 0
Next (Xy)
Do While ballCnt <= 74
gotcha = False
Randomize()
valueRnd = CInt(Int((75 * Rnd()) + 1))
For Xy = 1 To ballCnt + 1
If aryRnd(Xy) = valueRnd Then
gotcha = True
Exit For
End If
Next Xy
If Not gotcha Then
aryRnd(ballCnt + 1) = valueRnd
ballCnt = ballCnt + 1
End If
Loop