Set label long mode doesn't work

How-to
3

the code is shown below.It should scroll circle but it never worked.

lv_label_set_long_mode(AlarmInfoObj.EventPoint[ALARM_10], LV_LABEL_LONG_SROLL_CIRC);
    lv_label_set_long_mode(AlarmInfoObj.EventType[ALARM_10], LV_LABEL_LONG_SROLL_CIRC);
    lv_label_set_long_mode(AlarmInfoObj.EventDesc[ALARM_10], LV_LABEL_LONG_SROLL_CIRC);

    lv_obj_set_width(AlarmInfoObj.EventPoint[ALARM_10], 210);
    lv_obj_set_width(AlarmInfoObj.EventType[ALARM_10], 140);
    lv_obj_set_width(AlarmInfoObj.EventDesc[ALARM_10], 440);

    lv_label_set_text(AlarmInfoObj.EventPoint[ALARM_10], "12344567890ABCDEFGHIJKLMNOPQRSTUVWXYZ");
    lv_label_set_text(AlarmInfoObj.EventType[ALARM_10], "12344567890ABCDEFGHIJKLMNOPQRSTUVWXYZ");
    lv_label_set_text(AlarmInfoObj.EventDesc[ALARM_10], "12344567890ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopq");