Setting overridesorting for canvas does not take effect

When I want to add... To the special effects in the game Canvas And modify overrideSorting when , It is found that although the code is executed , But it didn't get the expected effect .

              Canvas _canvas = m_princeEffectGo.AddComponent<Canvas>();
              _canvas.overrideSorting = true;

Finally, I found that if Awake If you change it , Can't modify successfully , Only in Start Revision in China .

But then I used the framework of our project to write a test code to hang in UI Up test , Whether it's Awake still Start It will be carried out .

using UnityEngine;
using YoukiaUnity.App;

public class CanvasTest : MonoSwitch
{
    public GameObject canvas;
    public override void OnAwake()
    {
        base.OnAwake();
        GameObject _go = Instantiate(canvas, transform);
        Canvas _canvas = _go.AddComponent<Canvas>();
        _canvas.overrideSorting = true;
    }
    protected override void Initialization()
    {
        base.Initialization();
        GameObject _go = Instantiate(canvas, transform);
        Canvas _canvas = _go.AddComponent<Canvas>();
        _canvas.overrideSorting = true;
    }
}

Can't move why Awake Set in Canvas Of  overrideSorting Don't take effect ！ Take a brief note of ！