winform自动更新并实现文件的批量异步下载

public partial class update : Form
     {
         private WebClient client;
         int downfilenum = 0; //已下载文件数
         int downlistnum = 0;//总下载文件数
         List<string> list;
         private string URl;
         private string fileName;
         private const string applicationFile = "Setup";
 
         public update()
         {
             InitializeComponent();
         }
         //检测网络状态
         [DllImport("wininet.dll")]
         private extern static bool InternetGetConnectedState(out int connectionDescription, int reservedValue);
         private void update_Load(object sender, EventArgs e)
         {
             if (isConnected())
             {
                 client = new WebClient();
                 client.DownloadProgressChanged += new DownloadProgressChangedEventHandler(client_DownloadProgressChanged);
                 client.DownloadFileCompleted += new AsyncCompletedEventHandler(client_DownloadFileCompleted);
                 client.Proxy = WebRequest.DefaultWebProxy;
                 client.Proxy.Credentials = new NetworkCredential();
                 updateFile();
             }
             else
             {
                 lblMsg.Text = "网络连接异常，请联系管理员处理";
             }
         }
         /// <summary>
         /// 检测网络状态
         /// </summary>
         private bool isConnected()
         {
             int I = 0;
             bool state = InternetGetConnectedState(out I, 0);
             return state;
         }
         /// <summary>
         /// 获取xml文件，判断是否升级
         /// </summary>
         /// <param name="Dir"></param>
         /// <returns></returns>
         private string getSoftUpdate()
         {
             if (!File.Exists(Application.StartupPath + @" file://update.xml/"))
             {
                 return "nofile";
             }
             DateTime newDateTime;
             try
             {
                 SrmUpdate.updateSoapClient s = new SrmUpdate.updateSoapClient();
                 newDateTime = Convert.ToDateTime(s.GetSoftUpDateTime());//获取服务器最新更新日期
             }
             catch (Exception)
             {
 
                 throw;
             }
             DateTime oldDateTime;
             XmlDocument doc = new XmlDocument();
             doc.Load(Application.StartupPath + @" file://update.xml/");
             oldDateTime = Convert.ToDateTime(doc.SelectSingleNode("/AutoUpdate/SoftUpdateTime").Attributes["Date"].Value);
             return newDateTime >= oldDateTime ? "true" : "false";
         }
         /// <summary>
         /// 开始下载文件
         /// </summary>
         private void updateFile()
         {
             //判断系统有无更新，如果需要升级系统，开始下载
             string isUpdate = getSoftUpdate();
             if (isUpdate == "true")
             {
                 lblMsg.Text = "检测到版本有更新，准备升级";
                 progressBar1.Visible = true;
                 startDownload();
             }
             else if (isUpdate == "false")
             {
                 lblMsg.Text = "无需更新，直接启动系统";
                 runSystem();
             }
             else if (isUpdate == "nofile")
             {
                 lblMsg.Text = "缺少系统文件，请您联系管理员处理";
             }
         }
         /// <summary>
         /// 下载完成调用
         /// </summary>
         /// <param name="sender"></param>
         /// <param name="e"></param>
         void client_DownloadFileCompleted(object sender, AsyncCompletedEventArgs e)
         {
             downfilenum++;
             if (client != null) { client.CancelAsync(); }
             if (downfilenum < downlistnum) downLoadFile(list[downfilenum].ToString()); //下载剩余的
             if (downfilenum == downlistnum) { init(); } //初始化
         }
         //下载某个文件
         private void downLoadFile(string fileName)
         {
             downLoad(URl + fileName, Application.StartupPath + " file://temp//" + fileName, true); //异步下载远程文件
         }
         /// <summary>
         /// 下载进度条
         /// </summary>
         /// <param name="sender"></param>
         /// <param name="e"></param>
         void client_DownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e)
         {
             int a = e.ProgressPercentage;
             progressBar1.Value = a;
             lblMsg.Text = a + "% Downloading... ";
         }
        
         /// <summary>
         /// HTTP下载远程文件并保存本地的函数
         /// </summary>
         private void downLoad(string downAddress, string savePath, Boolean Async)
         {
             DirectoryInfo di = Directory.GetParent(savePath);
             if (!di.Exists) di.Create();
 
             WebClient client = new WebClient();  //再次new 避免WebClient不能I/O并发         
             if (Async)
             { //异步下载
                 client.DownloadProgressChanged += new DownloadProgressChangedEventHandler(client_DownloadProgressChanged);
                 client.DownloadFileCompleted += new AsyncCompletedEventHandler(client_DownloadFileCompleted);
                 client.DownloadFileAsync(new Uri(downAddress), savePath);
             }
             else client.DownloadFile(new Uri(downAddress), savePath);
         }
         /// <summary>
         /// 开始下载
         /// </summary>
         private void startDownload()
         {
             SrmUpdate.updateSoapClient ws = new SrmUpdate.updateSoapClient();
             URl = ws.GetSoftUpdateUrl();
             list = ws.GetSoftUpdateFileList();
             downlistnum = list.Count;
             fileName = list[0].Substring(list[0].LastIndexOf("/") + 1, list[0].Length - list[0].LastIndexOf("/") - 1);
             downLoad(URl + list[0], Application.StartupPath + " file://temp//" + fileName, true);
         }
         private void init()
         {
             string curdir = Application.StartupPath;
             DirectoryInfo theFolder = new DirectoryInfo(curdir + @"\temp");
             if (theFolder.Exists)
             {
                 copyDirectory(curdir + @"\temp", curdir);
             }
 
             if (Directory.Exists(curdir + @"\temp\")) Directory.Delete(curdir + @"\temp\", true); //删除临时目录
             runSystem();
         }
         /// <summary>
         /// 复制文件夹中的所有文件到指定文件夹
         /// </summary>
         /// <param name="DirectoryPath">源文件夹路径</param>
         /// <param name="DirAddress">保存路径</param>
         private void copyDirectory(string DirectoryPath, string DirAddress)//复制文件夹，
         {
             if(!Directory.Exists(DirAddress)) Directory.CreateDirectory(DirAddress);
             DirectoryInfo DirectoryArray = new DirectoryInfo(DirectoryPath);
             FileInfo[] Files = DirectoryArray.GetFiles();//获取该文件夹下的文件列表
             DirectoryInfo[] Directorys = DirectoryArray.GetDirectories();//获取该文件夹下的文件夹列表
             foreach (FileInfo theFile in Files)//逐个复制文件    
             {
                 //如果临时文件夹下存在与应用程序所在目录下的文件同名的文件，则删除应用程序目录下的文件  
                 if (File.Exists(DirAddress + "\\" + Path.GetFileName(theFile.FullName)))
                     File.Delete(DirAddress + "\\" + Path.GetFileName(theFile.FullName));
                 //将临时文件夹的文件移到应用程序所在的目录下  
                 File.Copy(theFile.FullName, DirAddress + "\\" + Path.GetFileName(theFile.FullName));
             }
             foreach (DirectoryInfo Dir in Directorys)//逐个获取文件夹名称，并递归调用方法本身    
             {
                 copyDirectory(DirectoryPath + "\\" + Dir.Name, DirAddress + "\\" + Dir.Name);
             }
         }
         /// <summary>
         /// 启动主程序
         /// </summary>
         private void runSystem()
         {
             //启动安装程序 
             this.lblMsg.Text = "正在启动主程序....";
             System.Diagnostics.Process.Start(Application.StartupPath + @"\SRMClientAppLoader.exe");
             this.Close();
         }
     }