static lv_style_t style_scr_act;
if (style_scr_act.prop_cnt == 0) {
lv_style_init(&style_scr_act);
lv_style_set_bg_opa(&style_scr_act, LV_OPA_COVER);
lv_obj_add_style(lv_scr_act(), &style_scr_act, 0);
}
lv_disp_get_default()->driver->screen_transp = 1;
lv_disp_set_bg_opa(lv_disp_get_default(), LV_OPA_TRANSP);
/* Empty the buffer, not emptying will cause the UI to be opaque */
lv_memset_00(lv_disp_get_default()->driver->draw_buf->buf_act,
lv_disp_get_default()->driver->draw_buf->size * sizeof(lv_color32_t));
lv_style_set_bg_opa(&style_scr_act, LV_OPA_TRANSP);
lv_obj_report_style_change(&style_scr_act);
设置透明层