UnityEvent绑定过程中，放在Start（）中绑定会报错（通过脚本添加UnityEvent事件脚本，绑定）

绑定事件放在OnEnable（）中不会报错，但是依然不可以立刻添加UnityEvent事件脚本紧接着立刻绑定事件。

或者在Start（）添加UnityEvent事件的脚本与绑定间隔时间长一些也不会报错。

示例：

创建点击对象方法

using UnityEngine;
using UnityEngine.Events;
using UnityEngine.EventSystems;
public class My3DObjOnClick : MonoBehaviour
{
    public UnityEvent events;
    private void OnMouseUpAsButton()
    {
       // if (EventSystem.current.IsPointerOverGameObject()) return;
        events.Invoke();
    }
}

报错案例1： 

创建绑定方法：

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Events;

public class Test : MonoBehaviour
{
    public Transform tar;//
    private void Start()
    {
        add_click_listener(Redian1_Click);
    }
    public void add_click_listener( UnityAction onclick)
    {
        tar.gameObject .AddComponent<My3DObjOnClick>();
         tar.GetComponent<My3DObjOnClick>().events.AddListener(onclick);
    }
    private void Redian1_Click()
    {
        Debug.Log("Redian1_Click");
    }
}

报错案例2：  

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Events;

public class Test : MonoBehaviour
{
    public Transform tar;
    private void Start()
    {  
        add_click_listener(Redian1_Click);
    }
    public void add_click_listener( UnityAction onclick)
    {
        tar.gameObject .AddComponent<My3DObjOnClick>(); 
        StartCoroutine("ceshi", onclick);
    }
    IEnumerator ceshi(UnityAction onclick)
    {
        yield return new WaitForEndOfFrame  ();
        //如果将时间延长，延长到5s则不会报错
       //  yield return new WaitForSeconds (5);
        tar.GetComponent<My3DObjOnClick>().events.AddListener(onclick);
    }
    private void Redian1_Click()
    {
        Debug.Log("Redian1_Click");
        // panelModel1_UICtrl.Open_Redian1();
    }
}

 报错案例3：  

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Events;

public class Test : MonoBehaviour
{
    public Transform tar;
    private void OnEnable()
    {   
        add_click_listener(Redian1_Click);
    }
    public void add_click_listener( UnityAction onclick)
    {
        tar.gameObject .AddComponent<My3DObjOnClick>();
        tar.GetComponent<My3DObjOnClick>().events.AddListener(onclick);
    }
    private void Redian1_Click()
    {
        Debug.Log("Redian1_Click");
    }
}

  不报错案例1：  

using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Events;
public class Test : MonoBehaviour
{
    public Transform tar;
    private void OnEnable()
    {
        add_click_listener(Redian1_Click);
    }
    public void add_click_listener( UnityAction onclick)
    {
        tar.gameObject .AddComponent<My3DObjOnClick>();
         StartCoroutine("ceshi", onclick);
    }
    IEnumerator ceshi(UnityAction onclick)
    {
        yield return new WaitForEndOfFrame  ();
        tar.GetComponent<My3DObjOnClick>().events.AddListener(Redian1_Click);
    }
    private void Redian1_Click()
    {
        Debug.Log("Redian1_Click");
    }
}

不报错案例2：   

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Events;

public class Test : MonoBehaviour
{
    public Transform tar;
    private void Start()
    {  
        add_click_listener(Redian1_Click);
    }
    public void add_click_listener( UnityAction onclick)
    {
        tar.gameObject .AddComponent<My3DObjOnClick>(); 
        StartCoroutine("ceshi", onclick);
    }
    IEnumerator ceshi(UnityAction onclick)
    {
       yield return new WaitForSeconds (5);
        tar.GetComponent<My3DObjOnClick>().events.AddListener(onclick);
    }
    private void Redian1_Click()
    {
        Debug.Log("Redian1_Click");
        // panelModel1_UICtrl.Open_Redian1();
    }
}

 不报错案例3：   

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Events;

public class Test : MonoBehaviour
{
    public Transform tar;
    private void OnEnable()
    {
        tar.gameObject .AddComponent<My3DObjOnClick>();
    }
    private void Update()
    {
        if (Input.GetKeyDown(KeyCode.W))
        {
            tar.GetComponent<My3DObjOnClick>().events.AddListener(Redian1_Click);
        }
    }
    private void Redian1_Click()
    {
        Debug.Log("Redian1_Click");
    }
}