Canvas draw text displaying

MIT App Inventor Help
1

I use a canvas to make a slider to my ListView.
it works well but the first time it is displayed there is no text in it...all other times text is displayed even if it changed...

I don't understand why.
I tried to move clear earlier, but with same result...

Screenshot_2020-11-26-10-07-06-840_appinventor.ai_jm_latour.MusicPlayer
Screenshot_2020-11-26-10-07-06-840_appinventor.ai_jm_latour.MusicPlayer1440×720 120 KB

fist time displaying
Screenshot_2020-11-26-10-08-14-495_appinventor.ai_jm_latour.MusicPlayer
Screenshot_2020-11-26-10-08-14-495_appinventor.ai_jm_latour.MusicPlayer1440×720 123 KB

other times

2
3

Oh sorry ! i forgot the bloks ! :see_no_evil:

image
image860×596 45.4 KB

image
image994×629 42.7 KB

DrawText is in "letter" but it seems not to be used the first time

4

The canvas must be visible in order for you to drawText. You do not set your canvas to be visible until after you have called drawText. After that it is OK, because the canvas is visible.

5

I did it, but without changes

image
image1163×592 59.3 KB

is there no way to refresh canvas ?

6

Canvas.Clear, then draw again

7

Hello TIMAI2..
Could you please show me how to using canvas DrawText to show text within the label which I set it invisable on Designer?
When I tried to connect the label block to call Canvas block it not connected.
Thank you.