Unity添加 SortingLayer 的方法

　　最近遇到一个需求，希望能通过脚本动态管理sorting layer，研究了一下文档发现，Unity没有开放对应的API接口，那么只能通过反射调用他的私有方法了
　　我封装的管理方法如下：
　　其中通过反射调用Unity私有方法的代码是我通过自己写的工具自动生成的，详情可以查看我的框架中反射查看器部分

using System;
using System.Collections;
using System.Collections.Generic;
using System.Reflection;
using UnityEditor;
using UnityEngine;

/// 

/// 编辑器功能增强
/// 
public class EditorExpand
{
    public static void AddSortLayerIfNotExist(string name)
    {
        if(!isExistShortLayer(name))
        {
            int index = GetSortingLayerCount();
            AddSortingLayer();
            SetSortingLayerName(index,name);
        }
    }

    public static bool isExistShortLayer(string name)
    {
        bool isExist = false;

        string[] layers = get_sortingLayerNames();

        for (int i = 0; i < layers.Length; i++)
        {
            if (name == layers[i])
            {
                isExist = true;
            }
        }

        return isExist;
    }
    public static string GetSortingLayer(int index)
    {
        BindingFlags flags = BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Static;
        Assembly ab = Assembly.Load("UnityEditor");
        Type type = ab.GetType("UnityEditorInternal.InternalEditorUtility");
        MethodInfo mi = type.GetMethod("GetSortingLayerName", flags);

        object[] objs = new object[1];
        objs[0] = index;

        return (string)mi.Invoke(null, objs);
    }

    public static int GetSortingLayerCount()
    {
        BindingFlags flags = BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Static;
        Assembly ab = Assembly.Load("UnityEditor");
        Type type = ab.GetType("UnityEditorInternal.InternalEditorUtility");
        MethodInfo mi = type.GetMethod("GetSortingLayerCount", flags);

        return (int)mi.Invoke(null, null);
    }

    public static void SetSortingLayerName(int index, string name)
    {
        BindingFlags flags = BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Static;
        Assembly ab = Assembly.Load("UnityEditor");
        Type type = ab.GetType("UnityEditorInternal.InternalEditorUtility");
        MethodInfo mi = type.GetMethod("SetSortingLayerName", flags);

        object[] objs = new object[2];
        objs[0] = index;
        objs[1] = name;

        mi.Invoke(null, objs);
    }

    public static void SetSortingLayerLocked(int index, bool locked)
    {
        BindingFlags flags = BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Static;
        Assembly ab = Assembly.Load("UnityEditor");
        Type type = ab.GetType("UnityEditorInternal.InternalEditorUtility");
        MethodInfo mi = type.GetMethod("SetSortingLayerLocked", flags);

        object[] objs = new object[2];
        objs[0] = index;
        objs[1] = locked;

        mi.Invoke(null, objs);
    }

    public static bool GetSortingLayerLocked(int index)
    {
        BindingFlags flags = BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Static;
        Assembly ab = Assembly.Load("UnityEditor");
        Type type = ab.GetType("UnityEditorInternal.InternalEditorUtility");
        MethodInfo mi = type.GetMethod("GetSortingLayerLocked", flags);

        object[] objs = new object[1];
        objs[0] = index;

        return (bool)mi.Invoke(null, objs);
    }

    public static void AddSortingLayer()
    {
        BindingFlags flags = BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Static;
        Assembly ab = Assembly.Load("UnityEditor");
        Type type = ab.GetType("UnityEditorInternal.InternalEditorUtility");
        MethodInfo mi = type.GetMethod("AddSortingLayer", flags);

        mi.Invoke(null, null);
    }

    public static string[] get_sortingLayerNames()
    {
        BindingFlags flags = BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Static;
        Assembly ab = Assembly.Load("UnityEditor");
        Type type = ab.GetType("UnityEditorInternal.InternalEditorUtility");

        MethodInfo mi = type.GetMethod("get_sortingLayerNames", flags);

        return (string[])mi.Invoke(null, null);
    }
}