关于U打包代码必须放到Editor目录下的问题

今天在写一个简单的打APK的工具功能时，刚开始打包脚本没有放到Editor目录下，产生了各种奇怪的问题，包括Assembly不可写，磁盘究竟是否满等。

以及AssetBundleBuild及各种其它类不存在等，放入Editor下后一切OK，脚本如下 ：

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

public class NewBehaviourScripts
{
    
    public static void buildab()
    {

    }

    static List<AssetBundleBuild> buildsMap = new List<AssetBundleBuild>(10);
    [MenuItem("xabc/bd")]
    public static void TestAb()
    {
        buildsMap.Clear();

        //shaders
        var allshadersBuild = new AssetBundleBuild();
        allshadersBuild.assetBundleName = "allShaders";
        allshadersBuild.assetBundleVariant = "ab";
        allshadersBuild.assetNames = new string[2] {
            "assets/res/shaders/DW_Particle Add_Mask.shader",
            "assets/res/shaders/allsvc.shadervariants", 
        };

        buildsMap.Add(allshadersBuild);

        //res
        var allResBuild = new AssetBundleBuild();
        allResBuild.assetBundleName = "allRes";
        allResBuild.assetNames = new string[3] {
            "assets/res/icon.png",
            "assets/res/xmat.mat",
            "assets/res/Cube.prefab",
        };

        buildsMap.Add(allResBuild);

        var dir = "d:/testab";
        if (!Directory.Exists(dir))
        {
            Directory.CreateDirectory(dir);
        }

        BuildPipeline.BuildAssetBundles("d:/testab", buildsMap.ToArray(), BuildAssetBundleOptions.DeterministicAssetBundle, BuildTarget.Android);


        Debug.Log("okkkkk");
    }
}