实现C/S程序的自动更新

最近在做一个.Net C/S的系统，需要实现自动更新。MS已经提供了ClickOnce，很方便，但是用起来不太习惯，还是决定自己写一个简单的。

自动更新无非文件比较、下载、启动程序几个步骤，其中文件比较可以通过手动在配置文件中维护版本号，也可以比较文件的MD5值，或者在.Net里还可以用Assembly或文件的版本号。因为怕麻烦，手动维护不考虑，剩下两者各有所长，都提供了以供选择。下载就比较简单了，http、ftp、WebService都可以选择。启动程序一般用System.Diagnostics.Process.Start就可以，我用的是AppDomain.ExecuteAssembly。

要自动生成文件版本信息，需要有个服务端，可以是WebService等等，我采用的是自己实现IHttpHandler，提供文件的版本信息和下载。

下面是UpdateHelper的类图和定义：

 

 

GetUpdateInfos、CheckIfNeedUpdate、DownloadFile分别是获取文件版本信息、比较文件是否是最新的、下载文件的作用，很简单。

1.     public static class UpdateHelper
2.     {
3.         public static UpdateInfo[] GetUpdateInfos()
4.         {
5.             HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Properties.Settings.Default.Server);
6.             request.Method = "GET";
7.             HttpWebResponse response = (HttpWebResponse)request.GetResponse();
8.             if (response.StatusCode == HttpStatusCode.OK)
9.             {
10.                 using (Stream output = request.GetResponse().GetResponseStream())
11.                 {
12.                     XmlSerializer xml = new XmlSerializer(typeof(UpdateInfo[]));
13.                     return (UpdateInfo[])xml.Deserialize(output);
14.                 }
15.             }
16.             else
17.             {
18.                 throw new Exception("Exception occurs on the server.");
19.             }
20.         }
22.         public static bool CheckIfNeedUpdate(UpdateInfo update)
23.         {
24.             if (!File.Exists(update.FileName))
25.             {
26.                 return true;
27.             }
28.             else
29.             {
30.                 switch (update.VersionType)
31.                 {
32.                     case VersionType.FileVersion:
33.                         return FileVersionInfo.GetVersionInfo(update.FileName).FileVersion != update.Version;
34.                     case VersionType.MD5:
35.                         using (FileStream file = File.OpenRead(update.FileName))
36.                         {
37.                             return Convert.ToBase64String(MD5.Create().ComputeHash(file)) != update.Version;
38.                         }
39.                     default: return false;
40.                 }
41.             }
42.         }
44.         public static void Update()
45.         {
46.             UpdateInfo[] updates = UpdateHelper.GetUpdateInfos();
47.             List<Thread> downloadsThreads = new List<Thread>();
48.             foreach (UpdateInfo update in updates)
49.             {
50.                 if (UpdateHelper.CheckIfNeedUpdate(update))
51.                 {
52.                     Thread thread = new Thread(delegate(object param) { UpdateHelper.DownloadFile((string)param); });
53.                     thread.Start(update.FileName);
54.                     downloadsThreads.Add(thread);
55.                 }
56.             }
57.             foreach (Thread thread in downloadsThreads) thread.Join();
58.         }
60.         public static void DownloadFile(string fileName)
61.         {
62.             HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Properties.Settings.Default.Server + "?download=" + fileName);
63.             request.Method = "GET";
64.             HttpWebResponse response = (HttpWebResponse)request.GetResponse();
65.             if (response.StatusCode == HttpStatusCode.OK)
66.             {
67.                 byte[] buffer = new byte[8096];
68.                 using (Stream output = request.GetResponse().GetResponseStream())
69.                 {
70.                     using (FileStream file = File.Open(fileName, FileMode.OpenOrCreate))
71.                     {
72.                         int length = output.Read(buffer, 0, buffer.Length);
73.                         while (length != 0)
74.                         {
75.                             file.Write(buffer, 0, length);
76.                             length = output.Read(buffer, 0, buffer.Length);
77.                         }
78.                     }
79.                 }
80.             }
81.             else
82.             {
83.                 throw new Exception("Exception occurs on the server.");
84.             }
85.         }
86.     }
88.     public class UpdateInfo
89.     {
90.         public UpdateInfo() { }
92.         public UpdateInfo(string filename, VersionType versionType, string version)
93.         {
94.             FileName = filename;
95.             VersionType = versionType;
96.             Version = version;
97.         }
98.         public string FileName;
99.         public VersionType VersionType;
100.         public string Version;
101.     }
103.     public enum VersionType
104.     {
105.         FileVersion,
106.         MD5
107.     }

UpdateServiceHandler定义：

1.  public class UpdateServiceHandler : IHttpHandler
2.     {
3.         #region IHttpHandler Members
5.         public bool IsReusable
6.         {
7.             get { return true; }
8.         }
10.         public void ProcessRequest(HttpContext context)
11.         {
12.             if (String.Equals(context.Request.RequestType, "GET", StringComparison.OrdinalIgnoreCase))
13.             {
14.                 string filename = context.Request.QueryString["download"];
15.                 UpdateInfoSection updateInfoSection = GetUpdateConfig();
17.                 if (String.IsNullOrEmpty(filename))
18.                 {
19.                     context.Response.ContentEncoding = Encoding.UTF8;
20.                     context.Response.ContentType = "text/xml";
21.                     foreach (UpdateInfo update in updateInfoSection.UpdateFiles.Values)
22.                     {
23.                         switch (update.VersionType)
24.                         {
25.                             case VersionType.FileVersion:
26.                                 update.Version = FileVersionInfo.GetVersionInfo(update.Path).FileVersion;
27.                                 break;
28.                             case VersionType.MD5:
29.                                 using (FileStream file = File.OpenRead(update.Path)) update.Version = Convert.ToBase64String(MD5.Create().ComputeHash(file));
30.                                 break;
31.                         }
32.                     }
33.                     XmlSerializer xml = new XmlSerializer(typeof(List<UpdateInfo>));
34.                     xml.Serialize(context.Response.Output, new List<UpdateInfo>(updateInfoSection.UpdateFiles.Values));
35.                 }
36.                 else
37.                 {
38.                     UpdateInfo update;
39.                     if (updateInfoSection.UpdateFiles.TryGetValue(filename, out update))
40.                     {
41.                         context.Response.ContentEncoding = Encoding.UTF8;
42.                         context.Response.ContentType = "application/x-msdownload";
43.                         context.Response.AppendHeader("Content-Disposition", "attachment;filename=" + filename);
44.                         context.Response.WriteFile(update.Path);
45.                     }
46.                     else
47.                     {
48.                         context.Response.ContentEncoding = Encoding.UTF8;
49.                         context.Response.ContentType = "text/html";
50.                         context.Response.Output.WriteLine("File {0} not fount.", filename);
51.                     }
53.                 }
54.             }
55.         }
57.         private UpdateInfoSection GetUpdateConfig()
58.         {
59.             UpdateInfoSection updateInfoSection = (UpdateInfoSection)ConfigurationManager.GetSection("ClientUpdateInfo");
60.             if (!updateInfoSection.Initialize)
61.             {
62.                 foreach (UpdateInfo update in updateInfoSection.UpdateFiles.Values)
63.                 {
64.                     if (String.IsNullOrEmpty(update.Path)) update.Path = Path.Combine(updateInfoSection.DefaultForlder, update.FileName);
65.                     update.Path = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, update.Path);
66.                 }
67.                 updateInfoSection.Initialize = true;
68.             }
69.             return updateInfoSection;
70.         }
72.         #endregion
73.     }
75.     public class UpdateInfoSection : ConfigurationSection
76.     {
77.         public string DefaultForlder;
78.         public Dictionary<string, UpdateInfo> UpdateFiles = new Dictionary<string, UpdateInfo>();
79.         public bool Initialize = false;
81.         protected override void DeserializeSection(System.Xml.XmlReader reader)
82.         {
83.             while (reader.Read())
84.             {
85.                 if (reader.NodeType == System.Xml.XmlNodeType.Element)
86.                 {
87.                     switch (reader.Name)
88.                     {
89.                         case "File":
90.                             string versionType = reader.GetAttribute("VersionType");
91.                             UpdateFiles.Add(reader.GetAttribute("FileName"),
92.                             new UpdateInfo(
93.                                 reader.GetAttribute("FileName"),
94.                                 String.IsNullOrEmpty(versionType) ? VersionType.FileVersion : (VersionType)Enum.Parse(typeof(VersionType), versionType, true),
95.                                 reader.GetAttribute("Version"),
96.                                 reader.GetAttribute("Path")));
97.                             break;
98.                         case "DefaultFolder":
99.                             DefaultForlder = reader.ReadString();
100.                             break;
101.                     }
102.                 }
103.             }
104.         }
105.     }
107.     public class UpdateInfo
108.     {
109.         public UpdateInfo() { }
111.         public UpdateInfo(string filename, VersionType versionType, string version, string path)
112.         {
113.             FileName = filename;
114.             VersionType = versionType;
115.             Version = version;
116.             Path = path;
117.         }
118.         public string FileName;
119.         [XmlIgnore]
120.         public string Path;
121.         public VersionType VersionType;
122.         public string Version;
123.     }
125.     public enum VersionType
126.     {
127.         FileVersion,
128.         MD5
129.     }

 

注意下其中UpdateInfo多了一个Path属性，表示文件的实际路径，不需要显示给客户端，因此加了XmlIgnore标记。

在服务端需要配置UpdateInfoSection项和UpdateServiceHandler的地址映射。

在<system.web>节<httpHandlers>下添加一项：

1.     <httpHandlers>
2.       <add verb="*" path="update.aspx" type="MyService.UpdateServiceHandler"/>
3.     </httpHandlers>

其中MyService.UpdateServiceHandler需要替换为UpdateServiceHandler的完整名称。

然后添加UpdateInfoSection项：

1.   <configSections>
2.     <section name="ClientUpdateInfo" type="MyService.UpdateInfoSection"/>
3.   </configSections>
5.   <ClientUpdateInfo>
6.     <DefaultFolder>bin</DefaultFolder>
7.     <File FileName ="log4net.dll"/>
8.     <File FileName ="Castle.Core.dll"/>
9.     <File FileName ="Castle.DynamicProxy2.dll"/>
10.     <File FileName ="Client.dll" Path ="bin/Client.exe" />
11.     <File FileName ="client.config" VersionType="MD5"/>
12.   </ClientUpdateInfo>

DefaultFolder是在没有为文件提供Path时默认的包含文件的目录，配置比较简单。

好了，现在可以打开update.aspx页面看到文件的版本信息

在update.aspx后加上参数的话，例如?download=log4net.dll，就可以下载文件了。

 

最后，客户端只需要更新并运行程序就可以了，当然还需要设置一下服务端的地址（Properties.Settings.Default.Server）：

1.  static class Program
2.     {
3.         /// <summary>
4.         /// The main entry point for the application.
5.         /// </summary>
6.         [STAThread]
7.         static void Main()
8.         {
9.             UpdateHelper.Update();            
11.             AppDomain domain = AppDomain.CreateDomain("client");
12.             domain.SetData("APP_CONFIG_FILE", "client.config");
13.             domain.ExecuteAssembly("Client.dll", AppDomain.CurrentDomain.Evidence, Environment.GetCommandLineArgs());
14.         }        
15.     }