aibis-dream/Assets/Scripts/Framework/OtherKit/FadeKit.cs

using System.Collections;
using DG.Tweening;
using UnityEngine;
using UnityEngine.UI;

namespace AibisDream.Framework
{
    public static class FadeKit
    {
        public static IEnumerator FadeInAsync(this Image image, float duration)
        {
            image.gameObject.SetActive(true);
            var tweener = image.DOBlendableColor(Color.white, duration);
            yield return tweener.WaitForCompletion();
        }

        public static void FadeIn(this Image image, float duration)
        {
            image.gameObject.SetActive(true);
            var tweener = image.DOBlendableColor(Color.white, duration);
        }

        public static IEnumerator FadeOutAsync(this Image image, float duration)
        {
            image.gameObject.SetActive(true);
            var tweener = image.DOBlendableColor(Color.clear, duration);
            yield return tweener.WaitForCompletion();
            image.gameObject.SetActive(false);
        }

        public static void FadeOut(this Image image, float duration)
        {
            image.gameObject.SetActive(true);
            image.DOBlendableColor(Color.clear, duration).onComplete += () =>
            {
                image.gameObject.SetActive(false);
            };
        }
    }
}