C# Winform 自动更新程序实例

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 = ;
            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。