Unity UGUI暫停按鈕切換圖片代碼

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

public class PauseContorl : MonoBehaviour
{
    bool isGamePause;
    //游戲暫停按鈕
    private GameObject pauseButtonObj;
    //當前暫停按鈕的圖片
    private Image currentPauseImage;
    //暫停按鈕Sprite 
    private Sprite pauseSprite;
    //開始按鈕Sprite 
    private Sprite startSprite;

    private void Start()
    {
        pauseButtonObj = GameObject.Find("PauseButton");
        pauseButtonObj.GetComponent<Button>().onClick.AddListener
         (
            delegate () { SetPause(); }
         );

        currentPauseImage = pauseButtonObj.GetComponent<Image>();

        pauseSprite = Resources.Load("Images/pause/pause", typeof(Sprite)) as Sprite;
        startSprite = Resources.Load("Images/pause/start", typeof(Sprite)) as Sprite;
    }

    //設置游戲是否暫停
    void SetPause()
    {
        if (isGamePause)
        {
            isGamePause = false;

            currentPauseImage.sprite = pauseSprite;
        }
        else
        {
            isGamePause = true;

            currentPauseImage.sprite = startSprite;
        }
    }
}