lvgl设置背景透明

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);
    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);

此代码段放置在对应的显示屏幕的初始化最前面