What is the refresh principle of moving translucent objects in LVGL? Why can I see the picture behind the translucency in real time?

[jianjunxia]

What is the refresh principle of moving translucent objects in LVGL? Why can I see the picture behind the translucency in real time?

I want to fill an object in the sliding process with the pixel value I want, hoping to achieve the effect of sliding a semi-transparent rectangle

[kisvegabor]

@jianjunxia

Why can I see the picture behind the translucency in real time?

Else it wouldn’t be translucent, or I don’t understand the question.

@jianjunxia

What is the refresh principle of moving translucent objects in LVGL?

During rendering LVGL finds the top most object which covers the area to refresh. In your case it will be the wallpaper. So LVGL draws the wallpaper first and after that the rectangle.

[jianjunxia]

thanks！i konw it