第一步：检查更新
检查更新其实无非就是去比较更新包的版本和本地软件版本，如果高则更新、低则不更新。怎么获取版本号方法很多，本案例是获取软件的配置文件。
private bool CheckUpdate(){bool result = false;try{string Cfg = TxtRead(exePath "\\Config.txt");ConfigLocal = JsonConvert.DeserializeObject<DTO_Config>(Cfg);CheckUpdateURL = ConfigLocal.AutoUpdateURL;Cfg = TxtRead(CheckUpdateURL "\\Config.txt");ConfigRemote = JsonConvert.DeserializeObject<DTO_Config>(Cfg);VersionR = ConfigRemote.Version;VersionL = ConfigLocal.Version;int VersionRemote = int.Parse(ConfigRemote.Version.Replace(".", ""));int VersionLocal = int.Parse(ConfigLocal.Version.Replace(".", ""));result = VersionRemote > VersionLocal;}catch { }return result;}
第二步：下载更新包
因为C/S的软件更新是面对所有用户，S端除了给C端提供基本的服务外，还可以给C端提供更新包。而这个S端可以是网络上的一个固定地址，也可以是局域网内一个公共盘。那下载更新包无非就是去访问服务端的文件，然后Copy下来或下载下来。下面给出访问网络和访问局域网两个案例：
A、访问远程网络地址这里采用的是WebClient
public void DownLoadFile(){if (!Directory.Exists(UpdateFiles)){Directory.CreateDirectory(UpdateFiles);}using (WebClient webClient = new WebClient()){try{webClient.DownloadFileCompleted = new AsyncCompletedEventHandler(client_DownloadFileCompleted);webClient.DownloadProgressChanged = new DownloadProgressChangedEventHandler(client_DownloadProgressChanged);webClient.DownloadFileAsync(new Uri(CheckUpdateURL "\\UpdateFile.rar"), UpdateFiles "\\UpdateFile.rar");}catch (WebException ex){MessageBox.Show(ex.Message, "系统提示", MessageBoxButtons.OK, MessageBoxIcon.Error);}}}
这里面应用到两个方法，DownloadProgressChanged，监听异步下载的进度；DownloadFileCompleted，监听完成异步文件下载；
private void client_DownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e){this.progressBarUpdate.Minimum = 0;this.progressBarUpdate.Maximum = (int)e.TotalBytesToReceive;this.progressBarUpdate.Value = (int)e.BytesReceived;this.lblPercent.Text = e.ProgressPercentage "%";}
private void client_DownloadFileCompleted(object sender, AsyncCompletedEventArgs e){if (e.Error != null){MessageBox.Show(e.Error.Message, "系统提示", MessageBoxButtons.OK, MessageBoxIcon.Error);}else{this.lblMessage.Text = "下载完成";//复制更新文件替换旧文件DirectoryInfo TheFolder = new DirectoryInfo(UpdateFiles);foreach (FileInfo NextFile in TheFolder.GetFiles()){File.Copy(NextFile.FullName, Application.StartupPath NextFile.Name, true);}}}
B、访问服务端公共盘，直接采用File.Copy
public void GetRemoteFile(){try{DirectoryInfo TheFolder = new DirectoryInfo(CheckUpdateURL);FileInfo[] FileList = TheFolder.GetFiles();this.progressBarUpdate.Minimum = 0;this.progressBarUpdate.Maximum = FileList.Length;foreach (FileInfo NextFile in FileList){if (NextFile.Name != "Config.txt"){File.Copy(NextFile.FullName, exePath "\\" NextFile.Name, true); }this.lblMessage.Text = "更新" NextFile.Name;this.progressBarUpdate.Value = 1;this.lblPercent.Text = "更新进度... " (this.progressBarUpdate.Value / FileList.Length) * 100 "%";}this.lblMessage.Text = "更新完成";//更改本地版本号为最新版本号ConfigLocal.Version = VersionR;string cfgs = JsonConvert.SerializeObject(ConfigLocal);TxtWrite(Application.StartupPath "\\Config.txt", cfgs);}catch (Exception ex){MessageBox.Show(ex.Message, "系统提示", MessageBoxButtons.OK, MessageBoxIcon.Error);}}
第三步：替换本地文件
这一步或许在第二步中已经实现了，如果你采用的是File.Copy。替换也就是复制粘贴的问题。采用WebClient下载了zip包，那还需解压一下压缩包然后再File.Copy。
