一个空场景，添加如下代码：

using System.Collections;using System.Collections.Generic;using UnityEngine;public class NewBehaviourScript : MonoBehaviour{    private void OnGUI()    {            }}

可以看到每帧有一个固定的内存gc，可以用useGUILayout开关来关闭其gc消耗：

using System.Collections;using System.Collections.Generic;using UnityEngine;public class NewBehaviourScript : MonoBehaviour{    private void Start()    {#if !UNITY_EDITOR        useGUILayout = false;#endif    }    private void OnGUI()    {            }}