AssetBundle系列——游戏资源打包（二）

本篇接着上一篇。上篇中说到的4步的代码分别如下所示：

(1)将资源打包成assetbundle，并放到自定目录下

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

public class CreateAssetBundle
{
    public static void Execute(UnityEditor.BuildTarget target)
    {
        string SavePath = AssetBundleController.GetPlatformPath(target);

        // 当前选中的资源列表
        foreach (Object o in Selection.GetFiltered(typeof(Object), SelectionMode.DeepAssets))
        {
            string path = AssetDatabase.GetAssetPath(o);

            // 过滤掉meta文件和文件夹
            if(path.Contains(".meta") || path.Contains(".") == false)
                continue;

            // 过滤掉UIAtlas目录下的贴图和材质(UI/Common目录下的所有资源都是UIAtlas)
            if (path.Contains("UI/Common"))
            {
                if ((o is Texture) || (o is Material))
                    continue;
            }

            path = SavePath + ConvertToAssetBundleName(path);
            path = path.Substring(, path.LastIndexOf('.'));
            path += ".assetbundle";

            BuildPipeline.BuildAssetBundle(o, null, path, BuildAssetBundleOptions.CollectDependencies | BuildAssetBundleOptions.CompleteAssets | BuildAssetBundleOptions.DeterministicAssetBundle, target);
        }

        // scene目录下的资源

        AssetDatabase.Refresh();
    }

    static string ConvertToAssetBundleName(string ResName)
    {
        return ResName.Replace('/', '.');
    }
}

(2)为每个assetbund生成MD5码，用于检查资源是否有修改

using UnityEngine;
using UnityEditor;
using System.IO;
using System.Xml;
using System.Collections;
using System.Collections.Generic;
using System.Security.Cryptography;

public class CreateMD5List
{
    public static void Execute(UnityEditor.BuildTarget target)
    {
        string platform = AssetBundleController.GetPlatformName(target);
        Execute(platform);
        AssetDatabase.Refresh();
    }

    public static void Execute(string platform)
    {
        Dictionary<string, string> DicFileMD5 = new Dictionary<string, string>();
        MD5CryptoServiceProvider md5Generator = new MD5CryptoServiceProvider();

        string dir = System.IO.Path.Combine(Application.dataPath, "AssetBundle/" + platform);
        foreach (string filePath in Directory.GetFiles(dir))
        {
            if (filePath.Contains(".meta") || filePath.Contains("VersionMD5") || filePath.Contains(".xml"))
                continue;

            FileStream file = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.Read);
            byte[] hash = md5Generator.ComputeHash(file);
            string strMD5 = System.BitConverter.ToString(hash);
            file.Close();

            string key = filePath.Substring(dir.Length + , filePath.Length - dir.Length - );

            if (DicFileMD5.ContainsKey(key) == false)
                DicFileMD5.Add(key, strMD5);
            else
                Debug.LogWarning("<Two File has the same name> name = " + filePath);
        }

        string savePath = System.IO.Path.Combine(Application.dataPath, "AssetBundle/") + platform + "/VersionNum";
        if (Directory.Exists(savePath) == false)
            Directory.CreateDirectory(savePath);

        // 删除前一版的old数据
        if (File.Exists(savePath + "/VersionMD5-old.xml"))
        {
            System.IO.File.Delete(savePath + "/VersionMD5-old.xml");
        }

        // 如果之前的版本存在，则将其名字改为VersionMD5-old.xml
        if (File.Exists(savePath + "/VersionMD5.xml"))
        {
            System.IO.File.Move(savePath + "/VersionMD5.xml", savePath + "/VersionMD5-old.xml");
        }

        XmlDocument XmlDoc = new XmlDocument();
        XmlElement XmlRoot = XmlDoc.CreateElement("Files");
        XmlDoc.AppendChild(XmlRoot);
        foreach (KeyValuePair<string, string> pair in DicFileMD5)
        {
            XmlElement xmlElem = XmlDoc.CreateElement("File");
            XmlRoot.AppendChild(xmlElem);

            xmlElem.SetAttribute("FileName", pair.Key);
            xmlElem.SetAttribute("MD5", pair.Value);
        }

        // 读取旧版本的MD5
        Dictionary<string, string> dicOldMD5 = ReadMD5File(savePath + "/VersionMD5-old.xml");
        // VersionMD5-old中有，而VersionMD5中没有的信息，手动添加到VersionMD5
        foreach (KeyValuePair<string, string> pair in dicOldMD5)
        {
            if (DicFileMD5.ContainsKey(pair.Key) == false)
                DicFileMD5.Add(pair.Key, pair.Value);
        }

        XmlDoc.Save(savePath + "/VersionMD5.xml");
        XmlDoc = null;
    }

    static Dictionary<string, string> ReadMD5File(string fileName)
    {
        Dictionary<string, string> DicMD5 = new Dictionary<string, string>();

        // 如果文件不存在，则直接返回
        if (System.IO.File.Exists(fileName) == false)
            return DicMD5;

        XmlDocument XmlDoc = new XmlDocument();
        XmlDoc.Load(fileName);
        XmlElement XmlRoot = XmlDoc.DocumentElement;

        foreach (XmlNode node in XmlRoot.ChildNodes)
        {
            if ((node is XmlElement) == false)
                continue;

            string file = (node as XmlElement).GetAttribute("FileName");
            string md5 = (node as XmlElement).GetAttribute("MD5");

            if (DicMD5.ContainsKey(file) == false)
            {
                DicMD5.Add(file, md5);
            }
        }

        XmlRoot = null;
        XmlDoc = null;

        return DicMD5;
    }
}

MD5列表如下所示：

<Files>
  <File FileName="Assets.Resources.BigLevelTexture.TestLevel.assetbundle" MD5="54-00-42-38-D5-86-43-A6-57-9D-7C-09-3A-F8-6E-10" />
  <File FileName="Assets.Resources.EquipmentTexture.Test001.assetbundle" MD5="A1-19-D4-04-17-94-18-61-60-99-35-25-3F-7C-39-93" />
  <File FileName="Assets.Resources.EquipmentTexture.Test002.assetbundle" MD5="CF-36-DA-C8-D2-DB-CE-FD-4A-BF-31-81-A1-D1-D2-21" />
  <File FileName="Assets.Resources.EquipmentTexture.Test003.assetbundle" MD5="EF-30-78-AE-F8-F4-A0-EC-5B-4E-45-3F-1E-EF-42-44" />
  <File FileName="Assets.Resources.EquipmentTexture.Test004.assetbundle" MD5="3D-5D-A7-01-D2-B1-20-5F-B9-89-C5-CB-40-96-EC-89" />
  <File FileName="Assets.Resources.PetTexture.Empty.assetbundle" MD5="D9-AC-54-F8-EB-AA-1C-36-8C-2B-6C-12-37-AB-3B-48" />
</Files>

(3)比较新旧MD5码，生成资源变更列表

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

public class CampareMD5ToGenerateVersionNum
{
    public static void Execute(UnityEditor.BuildTarget target)
    {
        string platform = AssetBundleController.GetPlatformName(target);
        Execute(platform);
        AssetDatabase.Refresh();
    }

    // 对比对应版本目录下的VersionMD5和VersionMD5-old，得到最新的版本号文件VersionNum.xml
    public static void Execute(string platform)
    {
        // 读取新旧MD5列表
        string newVersionMD5 = System.IO.Path.Combine(Application.dataPath, "AssetBundle/" + platform + "/VersionNum/VersionMD5.xml");
        string oldVersionMD5 = System.IO.Path.Combine(Application.dataPath, "AssetBundle/" + platform + "/VersionNum/VersionMD5-old.xml");

        Dictionary<string, string> dicNewMD5Info = ReadMD5File(newVersionMD5);
        Dictionary<string, string> dicOldMD5Info = ReadMD5File(oldVersionMD5);

        // 读取版本号记录文件VersinNum.xml
        string oldVersionNum = System.IO.Path.Combine(Application.dataPath, "AssetBundle/" + platform + "/VersionNum/VersionNum.xml");
        Dictionary<string, int> dicVersionNumInfo = ReadVersionNumFile(oldVersionNum);

        // 对比新旧MD5信息，并更新版本号，即对比dicNewMD5Info&&dicOldMD5Info来更新dicVersionNumInfo
        foreach (KeyValuePair<string, string> newPair in dicNewMD5Info)
        {
            // 旧版本中有
            if (dicOldMD5Info.ContainsKey(newPair.Key))
            {
                // MD5一样，则不变
                // MD5不一样，则+1
                // 容错：如果新旧MD5都有，但是还没有版本号记录的，则直接添加新纪录，并且将版本号设为1
                if (dicVersionNumInfo.ContainsKey(newPair.Key) == false)
                {
                    dicVersionNumInfo.Add(newPair.Key, );
                }
                else if (newPair.Value != dicOldMD5Info[newPair.Key])
                {
                    int num = dicVersionNumInfo[newPair.Key];
                    dicVersionNumInfo[newPair.Key] = num + ;
                }
            }
            else // 旧版本中没有，则添加新纪录，并=1
            {
                dicVersionNumInfo.Add(newPair.Key, );
            }
        }
        // 不可能出现旧版本中有，而新版本中没有的情况，原因见生成MD5List的处理逻辑

        // 存储最新的VersionNum.xml
        SaveVersionNumFile(dicVersionNumInfo, oldVersionNum);
    }

    static Dictionary<string, string> ReadMD5File(string fileName)
    {
        Dictionary<string, string> DicMD5 = new Dictionary<string, string>();

        // 如果文件不存在，则直接返回
        if (System.IO.File.Exists(fileName) == false)
            return DicMD5;

        XmlDocument XmlDoc = new XmlDocument();
        XmlDoc.Load(fileName);
        XmlElement XmlRoot = XmlDoc.DocumentElement;

        foreach (XmlNode node in XmlRoot.ChildNodes)
        {
            if ((node is XmlElement) == false)
                continue;

            string file = (node as XmlElement).GetAttribute("FileName");
            string md5 = (node as XmlElement).GetAttribute("MD5");

            if (DicMD5.ContainsKey(file) == false)
            {
                DicMD5.Add(file, md5);
            }
        }

        XmlRoot = null;
        XmlDoc = null;

        return DicMD5;
    }

    static Dictionary<string, int> ReadVersionNumFile(string fileName)
    {
        Dictionary<string, int> DicVersionNum = new Dictionary<string, int>();

        // 如果文件不存在，则直接返回
        if (System.IO.File.Exists(fileName) == false)
            return DicVersionNum;

        XmlDocument XmlDoc = new XmlDocument();
        XmlDoc.Load(fileName);
        XmlElement XmlRoot = XmlDoc.DocumentElement;

        foreach (XmlNode node in XmlRoot.ChildNodes)
        {
            if ((node is XmlElement) == false)
                continue;

            string file = (node as XmlElement).GetAttribute("FileName");
            int num = XmlConvert.ToInt32((node as XmlElement).GetAttribute("Num"));

            if (DicVersionNum.ContainsKey(file) == false)
            {
                DicVersionNum.Add(file, num);
            }
        }

        XmlRoot = null;
        XmlDoc = null;

        return DicVersionNum;
    }

    static void SaveVersionNumFile(Dictionary<string, int> data, string savePath)
    {
        XmlDocument XmlDoc = new XmlDocument();
        XmlElement XmlRoot = XmlDoc.CreateElement("VersionNum");
        XmlDoc.AppendChild(XmlRoot);

        foreach (KeyValuePair<string, int> pair in data)
        {
            XmlElement xmlElem = XmlDoc.CreateElement("File");
            XmlRoot.AppendChild(xmlElem);
            xmlElem.SetAttribute("FileName", pair.Key);
            xmlElem.SetAttribute("Num", XmlConvert.ToString(pair.Value));
        }

        XmlDoc.Save(savePath);
        XmlRoot = null;
        XmlDoc = null;
    }
}

如下图所示，根据VersionMD5.xml和VersionMD5-old.xml对比产生VersionNum.xml：

(4)将变更列表文件也打包成assetbundle

也就是讲VersionNum.xml打包后供下载：

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

public class CreateAssetBundleForXmlVersion
{
    public static void Execute(UnityEditor.BuildTarget target)
    {
        string SavePath = AssetBundleController.GetPlatformPath(target);
        Object obj = AssetDatabase.LoadAssetAtPath(SavePath + "VersionNum/VersionNum.xml", typeof(Object));
        BuildPipeline.BuildAssetBundle(obj, null, SavePath + "VersionNum/VersionNum.assetbundle", BuildAssetBundleOptions.CollectDependencies | BuildAssetBundleOptions.CompleteAssets | BuildAssetBundleOptions.DeterministicAssetBundle, target);

        AssetDatabase.Refresh();
    }

    static string ConvertToAssetBundleName(string ResName)
    {
        return ResName.Replace('/', '.');
    }
}