How to set the opa of lv-canvas?

I am using the lv_canvas to draw a meter, How to set the opa of the backgrond? Thanks.

Do you mean to make the background transparent?

Yes,I want to set the background of lv_canvas transparent.

I made some test and realized that there are some issues with canvas if you are using a transparent background. It should be improved in v6.1.

So the next questions are:

  • how would like to draw to the canvas
  • what is your LV_COLOR_DEPTH

Hello, you can use functions: