编辑器脚本，用于打包资源文件

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEditor;
using System.IO;
using System;
using System.Security.Cryptography;
using System.Text;
using LitJson;
/// <summary>
/// 编辑器脚本
/// </summary>
public class BuildBundle : Editor {

    [MenuItem("Tools/build")]
    public static void Build()
    {

        //生成bundle包
        BuildAB();

        //拷贝lua文件
        HandleLuaFile();

        //生成版本文件
        GenFileText();
    }
    //拷贝lua文件
    private static void HandleLuaFile()
    {
        string path = Application.dataPath + "/Lua/";
        string[] files = Directory.GetFiles(path, "*.lua");//搜索所有的lua文件

        string desPath = Application.streamingAssetsPath + "/";

        if (!Directory.Exists(desPath))
        {
            Directory.CreateDirectory(desPath);
        }

        for (int i = 0; i < files.Length; i++)
        {
            string fileName = Path.GetFileName(files[i]);
            string des = desPath + "/" + fileName;
            File.Copy(files[i], des);
        }
    }

    //生成bundle包
    private static void BuildAB()
    {
        string path = Application.streamingAssetsPath;
        if (Directory.Exists(path))
        {
            //递归删除字目录
            Directory.Delete(path, true);
        }

        //创建目录
        Directory.CreateDirectory(path);
        //资源打包
        BuildPipeline.BuildAssetBundles(path, 0, BuildTarget.StandaloneWindows64);
    }

    //获取文件夹中所有文件
    static List<string> files = new List<string>();
    static void Recusive(string path)
    {
        string[] fs = Directory.GetFiles(path);
        files.AddRange(fs);

        string[] dires = Directory.GetDirectories(path);
        foreach (var item in dires)
        {
            Recusive(item);
        }
    }

    //生成版本文件
    private static void GenFileText()
    {
        Dictionary<string, string> filesMd5 = new Dictionary<string, string>();
        string path = Application.streamingAssetsPath;

        files.Clear();
        Recusive(path);      

        foreach (var item in files)
        {
            if (Path.GetFileName(item) != ".meta")
            {
                string md5 = Md5File(item);
                string fileName = Path.GetFileName(item);

                filesMd5.Add(fileName, md5);
            }
        }
        //将文件名和文件MD5值写入版本文件
        StreamWriter writer = File.CreateText(path + "/file.txt");
        writer.Write(JsonMapper.ToJson(filesMd5));
        writer.Close();

        //刷新文件夹
        AssetDatabase.Refresh();
    }

    //计算文件的MD5值
    private static string Md5File(string file)
    {
        FileStream fs = new FileStream(file, FileMode.Open);
        MD5 md5 = MD5CryptoServiceProvider.Create();

        byte[] retVal = md5.ComputeHash(fs);
        fs.Close();

        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < retVal.Length; i++)
        {
            sb.Append(retVal[i].ToString("x2"));
        }

        return sb.ToString();
    }
}

资源下载解压与加载
在Android和IOS中streamingAssets文件夹是只读的，不可以写入，所有资源文件统一拷贝到persistentDataPath下使用
PC路径为C:\Users\Robyn\AppData\LocalLow\DefaultCompany\项目名\

using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using UnityEngine;
using LitJson;
//检查更新
public class ABUpdateManager : MonoBehaviour {
    string streamingPaht;
    string dataPath;
    string baseUrl = "http://192.168.108.19/StreamingAssets/";

    public static event System.Action Complete;

    void Start () {
        streamingPaht = Application.streamingAssetsPath + "/";
        dataPath = Application.persistentDataPath + "/";
        Debug.Log(dataPath);
        Debug.Log("检测本地沙盒目录");
        if (File.Exists(dataPath + "file.txt"))
        {
            Debug.Log("沙盒目录不为空");
            //开启协程,检查更新
            StartCoroutine(CheckUpdate());
        }else
        {
            Debug.Log("沙盒目录为空");
            //首次运行，拷贝StreamingAsset到PersistentDatapath
            CheckCompress();
        }
    }

    private IEnumerator CheckUpdate()
    {
        Debug.Log("获取远程file.txt文件");
        WWW www = new WWW(baseUrl + "file.txt");
        yield return www;

        if (www.error != null)
        {
            Debug.Log(www.error);
            yield return 0;
        }
        //获取远程本版文件
        Dictionary<string, string> fileMd5 = JsonMapper.ToObject<Dictionary<string, string>>(www.text);

        //获取本地版本文件
        string filePath = dataPath + "file.txt";
        Dictionary<string, string> localMd5 = JsonMapper.ToObject<Dictionary<string, string>>(File.ReadAllText(filePath));

        //比较差异

        foreach (var item in fileMd5)
        {
            Debug.Log("检测更新" + item.Key);
            if (localMd5.ContainsKey(item.Key))
            {
                if (localMd5[item.Key] != fileMd5[item.Key])
                {
                    Debug.Log("MD5不同，更新：" + item.Key);
                    //删除本地文件
                    File.Delete(dataPath + item.Key);
                    //下载远程文件
                    StartCoroutine(DownloadFile(item.Key));
                }
            }
            else
            {
                //本地文件缺失，下载服务器文件
                Debug.Log("文件缺失，直接下载" + item.Key);
                StartCoroutine(DownloadFile(item.Key));
            }
        }

        //更新file
        File.Delete(dataPath + "file.txt");
        File.WriteAllText(dataPath + "file.txt", www.text);

        Debug.Log("解压更新完成");
        if (Complete != null)
        {
            Complete();
        }
    }

    //下载更新文件
    private IEnumerator DownloadFile(string fileName)
    {
        WWW download = new WWW(baseUrl + fileName);
        yield return download;

        File.WriteAllBytes(dataPath + fileName, download.bytes);
        Debug.LogFormat("更新文件{0}成功", fileName);
    }

    //拷贝文件到沙盒
    private void CheckCompress()
    {
        string[] files = Directory.GetFiles(streamingPaht);

        foreach (var item in files)
        {
            string targetPath = dataPath + Path.GetFileName(item);

            //如果文件存在，拷贝会失败
            if (File.Exists(targetPath))
            {
                File.Delete(targetPath);
            }

            File.Copy(item, targetPath);
        }

        //解压完成，检测更新
        StartCoroutine(CheckUpdate());
    }

}

使用

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

public class LoadAB_Dependence : MonoBehaviour {
    //保存加载过的bundle包
    Dictionary<string, AssetBundle> loadedBundles = new Dictionary<string, AssetBundle>();
    Button createBtn;
    void Start () {
        createBtn = GetComponent<Button>();
        createBtn.onClick.AddListener(CreatePrefabs);
    }

    private void CreatePrefabs()
    {
        var perfab1 = LoadAB("perfabs.unity3d", "Cube");
        var perfab2 = LoadAB("perfabs.unity3d", "Capsule");

        Instantiate(perfab1);
        Instantiate(perfab2);

        TestLoadLua();
    }

    void TestLoadLua()
    {

        LuaLoader loader = new LuaLoader();

        string luastring = loader.LoadLua("hello.lua");

        Debug.Log(luastring);
    }

    //解压资源与寻找依赖包
    public GameObject LoadAB(string abName, string prefabName)
    {
       //加在总配置
        AssetBundle ab = GetBundle("StreamingAssets");
        AssetBundleManifest abm = ab.LoadAsset<AssetBundleManifest>("AssetBundleManifest");

        //加载依赖
        string[] depends = abm.GetAllDependencies(abName);
        for (int i = 0; i < depends.Length; i++)
        {
            GetBundle(depends[i]);
        }

        //加载ab包
        AssetBundle asset = GetBundle(abName);
        return asset.LoadAsset<GameObject>(prefabName);
    }

    //缓存bundle
    AssetBundle GetBundle(string bundName)
    {
        if (loadedBundles.ContainsKey(bundName))
        {
            return loadedBundles[bundName];
        }

        AssetBundle ab = AssetBundle.LoadFromFile(Path + bundName);
        loadedBundles.Add(bundName, ab);

        return ab;
    }

    string path;

    public string Path
    {
        get
        {
            if (path == null)
            {
               path = Application.persistentDataPath + "/";
            }
           return path;
        }

    }

}

public class LuaLoader
{
    public string LoadLua(string luaName)
    {
        //string path = Application.persistentDataPath + "/Lua/";
        string path = Application.persistentDataPath + "/";

        string str = File.ReadAllText(path + luaName);

        return str;
    }
}