思路：
①检查是否需要更新（通过数据库获取最新版本号和本地版本号进行比对（本地版本号可存在txt文件中，需要进行一定程度上的加密和解密操作））
②从指定目录下载最新版本的程序覆盖本地文件（下载的文件时压缩文件）
③将压缩文件进行程序内解压缩（有可能客户电脑未安装压缩软件，所以只能通过程序本身来进行解压）
④解压完成后调用主程序
实现：
下载：WebClient
1 if (webClient.IsBusy)//是否存在正在进行中的Web请求 2 { 3 webClient.CancelAsync(); 4 } 5 //为webClient添加事件 6 webClient.DownloadProgressChanged += new DownloadProgressChangedEventHandler(webClient_DownloadProgressChanged); 7 webClient.DownloadFileCompleted += new AsyncCompletedEventHandler(webClient_DownloadFileCompleted); 8 //开始下载 9 string path = exePath + @"\Update.RAR"; 10 webClient.DownloadFileAsync(new Uri(this.txtFilePath.Text), path);
1 private void webClient_DownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e) 2 { 3 4 this.progressBar1.Value = e.ProgressPercentage; 5 this.lbl_pro.Text = e.ProgressPercentage.ToString() + "%"; 6 this.lbl_detail.Text = string.Format("Downloading....，{0}/{1}(byte)" 7 , e.BytesReceived 8 , e.TotalBytesToReceive); 9 if (e.TotalBytesToReceive == e.BytesReceived) 10 { 11 this.lbl_detail.Text = ("DownLoad success.Update now, wait a second！"); 12 } 13 }
1 private void webClient_DownloadFileCompleted(object sender, AsyncCompletedEventArgs e) 2 { 3 if (e.Cancelled) 4 { 5 DevExpress.XtraEditors.XtraMessageBox.Show("Download is canceled!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error, MessageBoxDefaultButton.Button1); 6 return; 7 } 8 else 9 { 10 11 if (this.lbl_detail.Text == ("DownLoad success.Update now, wait a second！")) 12 { 13 Thread t = new Thread(//实际上进行更新的方法); 14 CheckForIllegalCrossThreadCalls = false; 15 t.Start(); 16 } 17 18 } 19 }