上一次我们学习了如何将资源进行打包。这次就可以用上场了,我们来探讨一下手游资源的增量更新策略。注意哦,只是资源哦。关于代码的更新,我们稍后再来研究。理论上这个方案可以使用各种静态资源的更新,不仅仅是assetbundle打包的。
(转载请注明原文地址http://www.voidcn.com/article/p-uzevsxxx-eo.html)
现在的手游安装有几种方式。一种是安装的时候就把程序和资源安装到本地。另外一种是只安装程序和少量的必要资源,然后在启动的时候再把缺少的资源下载完整。手游一般不建议和传统页游一样,在运行过程中加载资源,那样做会导致用户体验会比较差些。上述的两种安装模式,在更新资源上本质都是相同的。都是比较服务器资源的版本和本地资源的版本,以确定哪些资源要下载(包括需要更新的和新增的)。
? ? ? ? 1.资源打包。
资源打包之前,要先规划好资源之间的相互依赖关系。把一些共性的东西抽取出来,尽量减少不必要的耦合。一些比较好的做法有,所有物件尽可能做成Prefab,场景上的东西越少越好,“一切都是动态加载”。
? ? ? ??2.生成文件MD5
关于文件的MD5,这里就不详细描述了。大家可以简单理解它为一个文件的状态标记。如果文件有更改,那么它的md5一定是改变的,单纯的移动文件是不会更改的。md5验证还可以起到安全验证的作用,保证本地文件不被篡改。举个例子,我们经常从网上上下载软件时,一般都会给出一个md5值,你下载后,对比一下已下载文件的md5值,就可以知道文件有没有被篡改。在版本发布时,我们需要对所有打包好的文件计算md5值,然后保存在一个配置文件中。关于这部分的工作,我之前写过一个可视化小工具(
https://github.com/kenro/File_Md5_Generator),现在分享给大家。如果大家觉得有用,记得打星哦:)
? ? ? ??3.版本比较
先加载本地的version.txt,将结果缓存起来。下载服务器的version.txt,与本地的version进行比较,筛选出需要更新和新增的资源
? ? ? ??4.下载资源
依次下载更新的资源,如果本地已经有旧资源,则替换之,否则就新建保存起来
? ? ? ??5.更新本地版本配置文件version.txt
用服务器的version.txt替换掉本地的version.txt。这样做是为了确保下次启动的时候,不会再重复更新了。
? ? ? ??6.从本地加载assetbundle进行测试显示。
这里将一个模型制成Prefab,打包成assetbundle。程序从本地加载后,显示在场景中
? ? ? ??7.更新服务器的assetbundle,重新生成版本号文件。
? ? ? ??8.重复6的步骤
我们可以验证,我们的程序不用任何改动,资源已经实现了更新。场景中显示的已经是最新的模型了。
关于上述的流程,我写了一个小的演示demo。我这里没有用到web服务器,而是将本地的另外一个文件夹作为资源服务器目录。这里的目录只针对windows下的版本进行测试。如果要在手机平台上,需要记得更新相关的路径。
- using?UnityEngine;??
- using?System.Collections;??
- using?System.Collections.Generic;??
- using?System.Text;??
- using?System.IO;??
- ??
- public?class?ResUpdate?:?MonoBehaviour??
- {??
- ????public?static?readonly?string?VERSION_FILE?=?"version.txt";??
- ????public?static?readonly?string?LOCAL_RES_URL?=?"file://"?+?Application.dataPath?+?"/Res/";??
- ????public?static?readonly?string?SERVER_RES_URL?=?"file:///C:/Res/";??
- ????public?static?readonly?string?LOCAL_RES_PATH?=?Application.dataPath?+?"/Res/";??
- ??
- ????private?Dictionary<string,?string>?LocalResVersion;??
- ????private?Dictionary<string,?string>?ServerResVersion;??
- ????private?List<string>?NeedDownFiles;??
- ????private?bool?NeedUpdateLocalVersionFile?=?false;??
- ??
- ????void?Start()??
- ????{??
- ??????????
- ????????LocalResVersion?=?new?Dictionary<string,?string>();??
- ????????ServerResVersion?=?new?Dictionary<string,?string>();??
- ????????NeedDownFiles?=?new?List<string>();??
- ??
- ??????????
- ????????StartCoroutine(DownLoad(LOCAL_RES_URL?+?VERSION_FILE,?delegate(WWW?localVersion)??
- ????????{??
- ??????????????
- ????????????ParseVersionFile(localVersion.text,?LocalResVersion);??
- ??????????????
- ????????????StartCoroutine(this.DownLoad(SERVER_RES_URL?+?VERSION_FILE,?delegate(WWW?serverVersion)??
- ????????????{??
- ??????????????????
- ????????????????ParseVersionFile(serverVersion.text,?ServerResVersion);??
- ??????????????????
- ????????????????CompareVersion();??
- ??????????????????
- ????????????????DownLoadRes();??
- ????????????}));??
- ??
- ????????}));??
- ????}??
- ??
- ??????
- ????private?void?DownLoadRes()??
- ????{??
- ????????if?(NeedDownFiles.Count?==?0)??
- ????????{??
- ????????????UpdateLocalVersionFile();??
- ????????????return;??
- ????????}??
- ??
- ????????string?file?=?NeedDownFiles[0];??
- ????????NeedDownFiles.RemoveAt(0);??
- ??
- ????????StartCoroutine(this.DownLoad(SERVER_RES_URL?+?file,?delegate(WWW?w)??
- ????????{??
- ??????????????
- ????????????ReplaceLocalRes(file,?w.bytes);??
- ????????????DownLoadRes();??
- ????????}));??
- ????}??
- ??
- ????private?void?ReplaceLocalRes(string?fileName,?byte[]?data)??
- ????{??
- ????????string?filePath?=?LOCAL_RES_PATH?+?fileName;??
- ????????FileStream?stream?=?new?FileStream(LOCAL_RES_PATH?+?fileName,?FileMode.Create);??
- ????????stream.Write(data,?0,?data.Length);??
- ????????stream.Flush();??
- ????????stream.Close();??
- ????}??
- ??
- ??????
- ????private?IEnumerator?Show()??
- ????{??
- ????????WWW?asset?=?new?WWW(LOCAL_RES_URL?+?"cube.assetbundle");??
- ????????yield?return?asset;??
- ????????AssetBundle?bundle?=?asset.assetBundle;??
- ????????Instantiate(bundle.Load("Cube"));??
- ????????bundle.Unload(false);??
- ????}??
- ??
- ??????
- ????private?void?UpdateLocalVersionFile()??
- ????{??
- ????????if?(NeedUpdateLocalVersionFile)??
- ????????{??
- ????????????StringBuilder?versions?=?new?StringBuilder();??
- ????????????foreach?(var?item?in?ServerResVersion)??
- ????????????{??
- ????????????????versions.Append(item.Key).Append(",").Append(item.Value).Append("n");??
- ????????????}??
- ??
- ????????????FileStream?stream?=?new?FileStream(LOCAL_RES_PATH?+?VERSION_FILE,?FileMode.Create);??
- ????????????byte[]?data?=?Encoding.UTF8.GetBytes(versions.ToString());??
- ????????????stream.Write(data,?data.Length);??
- ????????????stream.Flush();??
- ????????????stream.Close();??
- ????????}??
- ??????????
- ????????StartCoroutine(Show());??
- ????}??
- ??
- ????private?void?CompareVersion()??
- ????{??
- ????????foreach?(var?version?in?ServerResVersion)??
- ????????{??
- ????????????string?fileName?=?version.Key;??
- ????????????string?serverMd5?=?version.Value;??
- ??????????????
- ????????????if?(!LocalResVersion.ContainsKey(fileName))??
- ????????????{??
- ????????????????NeedDownFiles.Add(fileName);??
- ????????????}??
- ????????????else??
- ????????????{??
- ??????????????????
- ????????????????string?localMd5;??
- ????????????????LocalResVersion.TryGetValue(fileName,?out?localMd5);??
- ????????????????if?(!serverMd5.Equals(localMd5))??
- ????????????????{??
- ????????????????????NeedDownFiles.Add(fileName);??
- ????????????????}??
- ????????????}??
- ????????}??
- ??????????
- ????????NeedUpdateLocalVersionFile?=?NeedDownFiles.Count?>?0;??
- ????}??
- ??
- ????private?void?ParseVersionFile(string?content,?Dictionary<string,?string>?dict)??
- ????{??
- ????????if?(content?==?null?||?content.Length?==?0)??
- ????????{??
- ????????????return;??
- ????????}??
- ????????string[]?items?=?content.Split(new?char[]?{?'n'?});??
- ????????foreach?(string?item?in?items)??
- ????????{??
- ????????????string[]?info?=?item.Split(new?char[]?{?','?});??
- ????????????if?(info?!=?null?&&?info.Length?==?2)??
- ????????????{??
- ????????????????dict.Add(info[0],?info[1]);??
- ????????????}??
- ????????}??
- ??
- ????}??
- ??
- ????private?IEnumerator?DownLoad(string?url,?HandleFinishDownload?finishFun)??
- ????{??
- ????????WWW?www?=?new?WWW(url);??
- ????????yield?return?www;??
- ????????if?(finishFun?!=?null)??
- ????????{??
- ????????????finishFun(www);??
- ????????}??
- ????????www.Dispose();??
- ????}??
- ??
- ????public?delegate?void?HandleFinishDownload(WWW?www);??
- }??
using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using System.IO;
public class ResUpdate : MonoBehaviour
{
public static readonly string VERSION_FILE = "version.txt";
public static readonly string LOCAL_RES_URL = "file://" + Application.dataPath + "/Res/";
public static readonly string SERVER_RES_URL = "file:///C:/Res/";
public static readonly string LOCAL_RES_PATH = Application.dataPath + "/Res/";
private Dictionary<string,string> LocalResVersion;
private Dictionary<string,string> ServerResVersion;
private List<string> NeedDownFiles;
private bool NeedUpdateLocalVersionFile = false;
void Start()
{
//初始化
LocalResVersion = new Dictionary<string,string>();
ServerResVersion = new Dictionary<string,string>();
NeedDownFiles = new List<string>();
//加载本地version配置
StartCoroutine(DownLoad(LOCAL_RES_URL + VERSION_FILE,delegate(WWW localVersion)
{
//保存本地的version
ParseVersionFile(localVersion.text,LocalResVersion);
//加载服务端version配置
StartCoroutine(this.DownLoad(SERVER_RES_URL + VERSION_FILE,delegate(WWW serverVersion)
{
//保存服务端version
ParseVersionFile(serverVersion.text,ServerResVersion);
//计算出需要重新加载的资源
CompareVersion();
//加载需要更新的资源
DownLoadRes();
}));
}));
}
//依次加载需要更新的资源
private void DownLoadRes()
{
if (NeedDownFiles.Count == 0)
{
UpdateLocalVersionFile();
return;
}
string file = NeedDownFiles[0];
NeedDownFiles.RemoveAt(0);
StartCoroutine(this.DownLoad(SERVER_RES_URL + file,delegate(WWW w)
{
//将下载的资源替换本地就的资源
ReplaceLocalRes(file,w.bytes);
DownLoadRes();
}));
}
private void ReplaceLocalRes(string fileName,byte[] data)
{
string filePath = LOCAL_RES_PATH + fileName;
FileStream stream = new FileStream(LOCAL_RES_PATH + fileName,FileMode.Create);
stream.Write(data,data.Length);
stream.Flush();
stream.Close();
}
//显示资源
private IEnumerator Show()
{
WWW asset = new WWW(LOCAL_RES_URL + "cube.assetbundle");
yield return asset;
AssetBundle bundle = asset.assetBundle;
Instantiate(bundle.Load("Cube"));
bundle.Unload(false);
}
//更新本地的version配置
private void UpdateLocalVersionFile()
{
if (NeedUpdateLocalVersionFile)
{
StringBuilder versions = new StringBuilder();
foreach (var item in ServerResVersion)
{
versions.Append(item.Key).Append(",").Append(item.Value).Append("n");
}
FileStream stream = new FileStream(LOCAL_RES_PATH + VERSION_FILE,FileMode.Create);
byte[] data = Encoding.UTF8.GetBytes(versions.ToString());
stream.Write(data,data.Length);
stream.Flush();
stream.Close();
}
//加载显示对象
StartCoroutine(Show());
}
private void CompareVersion()
{
foreach (var version in ServerResVersion)
{
string fileName = version.Key;
string serverMd5 = version.Value;
//新增的资源
if (!LocalResVersion.ContainsKey(fileName))
{
NeedDownFiles.Add(fileName);
}
else
{
//需要替换的资源
string localMd5;
LocalResVersion.TryGetValue(fileName,out localMd5);
if (!serverMd5.Equals(localMd5))
{
NeedDownFiles.Add(fileName);
}
}
}
//本次有更新,同时更新本地的version.txt
NeedUpdateLocalVersionFile = NeedDownFiles.Count > 0;
}
private void ParseVersionFile(string content,Dictionary<string,string> dict)
{
if (content == null || content.Length == 0)
{
return;
}
string[] items = content.Split(new char[] { 'n' });
foreach (string item in items)
{
string[] info = item.Split(new char[] { ',' });
if (info != null && info.Length == 2)
{
dict.Add(info[0],info[1]);
}
}
}
private IEnumerator DownLoad(string url,HandleFinishDownload finishFun)
{
WWW www = new WWW(url);
yield return www;
if (finishFun != null)
{
finishFun(www);
}
www.Dispose();
}
public delegate void HandleFinishDownload(WWW www);
}
资源更新的原理,本质上都是相似的。我之前也从事过页游的开发,资源更新流程也类似。所以技术的本质是掌握思维方式,平台和语言都是永远在变的。我们最后归纳一下流程:比较服务端的资源版本和本地的资源版本,找出需要更新的资源,然后依次下载。如果大家有更好的策略,欢迎分享探讨 ken@iamcoding.com。
http://pan.baidu.com/s/1mgNnR8O
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