lvgl roller(滑动列表控件)

源代码：

static void roller_event_handler(lv_obj_t * obj, lv_event_t event)
{
  if (event == LV_EVENT_VALUE_CHANGED) {
    char buf[32];
    lv_roller_get_selected_str(obj, buf, sizeof(buf));
    printf("Selected month: %s\n", buf);
  }
}

  //21 滚动对象
  //21.1 创建一个滚动对象
  lv_obj_t *roller1 = lv_roller_create(lv_scr_act(), NULL);
  lv_roller_set_options(roller1,
    "1.January\n"
    "2.February\n"
    "3.March\n"
    "4.April\n"
    "5.May\n"
    "6.June\n"
    "7.July\n"
    "8.August\n"
    "9.September\n"
    "10.October\n"
    "11.November\n"
    "12.December",
    LV_ROLLER_MODE_INIFINITE);

  //21.2 设置可见的行个数
  lv_roller_set_visible_row_count(roller1, 4);
  lv_roller_set_align(roller1, LV_LABEL_ALIGN_LEFT);
  lv_obj_align(roller1, NULL, LV_ALIGN_CENTER, 180, 220);
  lv_obj_set_event_cb(roller1, roller_event_handler);

效果演示：