Unity实现UI光晕效果（发光效果）

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
 
public class MoonFlash : MonoBehaviour {
 
 private CanvasGroup moonCanvasGroup;
 private float flashSpeed=0.2f;//光晕闪动速度
 private bool isOn = true;
 private float maxAlpha = 0.6f;//显示的最高alpha值
 private float minAlpha = 0.05f;//显示的最低alpha值
 
 void Start () {
 moonCanvasGroup = GetComponent<CanvasGroup>();
 }
 
 void Update () {
 if (moonCanvasGroup.alpha < maxAlpha && isOn)
 {
  moonCanvasGroup.alpha +=flashSpeed* Time.deltaTime;
 }
 else {
  isOn = false;
  moonCanvasGroup.alpha -=flashSpeed* Time.deltaTime;
  if (moonCanvasGroup.alpha <minAlpha) {
  isOn = true;
  }
 }
 }
}