sked/Assets/Script/UI/ButtonFocus.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class ButtonFocus : MonoBehaviour
{
    public List<ButtonFocusItem> listbfItem;
    public int idx = 0;

    void Start()
    {
        listbfItem[idx].Focus();
    }
    void Update()
    {
        if(Input.GetKeyDown(KeyCode.DownArrow))
        {
            listbfItem[idx].Focus(false);
            idx = idx + 1 < listbfItem.Count ? idx + 1 : 0;
            listbfItem[idx].Focus(true);
        }
        else if(Input.GetKeyDown(KeyCode.UpArrow))
        {
            listbfItem[idx].Focus(false);
            idx = -1 < idx - 1 ? idx - 1 : listbfItem.Count - 1;
            listbfItem[idx].Focus(true);
        }
        else if(Input.GetKeyDown(KeyCode.Return))
        {
            listbfItem[idx].OnFocusSelect();
        }
    }
}