Android Question Refresh needed for ToastMessageBox / button refresh


Licensed User
Hi everybody,
I coded the example (B4ABeginners%20GuideV3_2.pdf) page 122 ( display of a grid with buttons) and modified it.

r = Rnd(1,4)
Select r
Case 1
btn.Color = Colors.Red
Case 2
btn.Color = Colors.Blue
Case 3
btn.Color = Colors.Green
Case 4
btn.Color = Colors.Yellow
End Select

Then I added a loop in my main activity. Works fine as long as I use a msgbox for creating the next round of buttons - the colors change perfectly.
But when I replace the msgbox by a ToastMessageShow no refresh of the buttons are performed, the colors stay the same - probably because there is no click event forcing the refresh?

What can I do?