PO/Assets/Inventory/SpawnButton.cs

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

public class SpawnButton : MonoBehaviour
{
    [SerializeField] private Button buttonPrefab;
    [SerializeField] private GameObject parent;

    [SerializeField] private List<Button> allButtonLinks = new List<Button>();

    [SerializeField] private float distX;
    [SerializeField] private float distY;

    [SerializeField] private int maxHeroesInRow = 3;
    [SerializeField] private int maxHeroesInColumn = 3;

    public int maxHeroButOnPage;
    [SerializeField] private int page;


    private void Start()
    {
        page = 0;
        maxHeroButOnPage = maxHeroesInRow * maxHeroesInColumn;
        InstantiateEquipmentButton(0, maxHeroButOnPage);
    }

    public void ChangePage(int _page)
    {
        if ((page + _page) * maxHeroButOnPage - Inventory.main.localplayerEquipment.Count < 0)
        {
            if (page + _page > -1)
            {
                page += _page;
            }

            foreach (Transform child in transform)
            {
                GameObject.Destroy(child.gameObject);
            }

            InstantiateEquipmentButton(page * (maxHeroButOnPage), (page + 1) * (maxHeroButOnPage));
        }
    }

    public void InstantiateEquipmentButton(int _begin, int _end)
    {
        for (int i = 0; i < allButtonLinks.Count; i++)
        {
            Destroy(allButtonLinks[i]);
        }
        allButtonLinks.Clear();

        float _x = 0;
        float _y = 0;
        int _counter = 0;

        for (int i = _begin; i < _end; i++)
        {
            if (i > Inventory.main.localplayerEquipment.Count - 1)
            {
                break;
            }

            Button link = Instantiate(buttonPrefab, parent.transform);

            link.transform.GetComponent<EquipmentButton>().num = i;
            link.transform.localPosition = new Vector3(_x, _y, 0);
            link.image.sprite = Inventory.main.localplayerEquipment[i].GetComponent<Equipment>().equipmentConfig.equipmentCharacteristics.sprite;

            _x += gameObject.GetComponent<RectTransform>().rect.width + distX;

            _counter += 1;
            if (_counter % maxHeroesInRow == 0)
            {
                _x = 0;
                _y -= gameObject.GetComponent<RectTransform>().rect.height + distY;
            }

            allButtonLinks.Add(link);
        }
    }
}