Unity函数Awake和OnEnable执行顺序小坑

Awake: This function is always called before any Start functions and also just after a prefabis instantiated. (If a GameObject is inactive during start up Awake is not called until it is made active.)

OnEnable: (only called if the Object is active): This function is called just after the object is enabled. This happens when a MonoBehaviour instance is created, such as when a level is loaded or a GameObject with the script component is instantiated.

check the exec order here

今天做工时候遇到了一个问题，我在Mono A的 Awake 中把Mono A的实例绑定到了GameManager里，然后再Mono B的 OnEnable 中获取Mono A的实例，结果跳了个空引用异常。
把我惊了，原来这一年多来我一直在一个误区里。

我以前一直认为是当场景里所有的 Awake 跑完才开始跑 OnEnable()。但其实不是这样的。

当一个Mono的 Awake 跑完以后会接着跑他的 OnEnable , 接着才去跑其他物体的 Awake 和 OnEnable。

随便写两行测试一下就知道了。

public class TesterA1 : MonoBehaviour
{
    private Type m_type = null;

    private void Awake()
    {
        m_type = this.GetType();
        Debug.Log($"{m_type.Name} awake");
    }

    private void OnEnable()
    {
        Debug.Log($"{m_type.Name} on enable");
    }
}

public class TesterB1 : MonoBehaviour
{
    // Start is called before the first frame update
    private Type m_type = null;

    private void Awake()
    {
        m_type = this.GetType();
        Debug.Log($"{m_type.Name} awake");
    }

    private void OnEnable()
    {
        Debug.Log($"{m_type.Name} on enable");
    }
}

public class TesterC1 : MonoBehaviour
{
    private Type m_type = null;

    private void Awake()
    {
        m_type = this.GetType();
        Debug.Log($"{m_type.Name} awake");
    }

    private void OnEnable()
    {
        Debug.Log($"{m_type.Name} on enable");
    }
}

都整上一样的内容，A和C绑在物体tester01上，B绑在物体tester02上。