<pre name="code" class="csharp">string path = Server.MapPath("aa\\ahaakladahsasdas_bb.zip");              string newfileName = "";              if (File.Exists(path))              {                  FileInfo fi = new FileInfo(path);                  Response.Clear();//Clear 方法删除缓冲区中的所有 HTML 输出。但 Clear 方法只删除响应正文                  //而不删除响应标题。可以用该方法处理错误情况。                  Response.ClearHeaders();                  Response.Buffer = false;//这句话的意思就是指明输出页面是否被缓冲，当属性值为True时，                  //服务器将不会向客户端发送任何信息，直到所有程序执行完或者遇到                   //Response.Flush或Response.End语句，才会释放缓冲区的信息。                  string filename = Path.GetFileName(path);                  newfileName = newfileName + filename.Substring(filename.LastIndexOf("."));                  Response.Clear();                  Response.ClearHeaders();                  Response.Buffer = false;                  newfileName = HttpUtility.UrlEncode(newfileName);// 这一步弹出下载保存的对话框，出现文件名乱码，但变量中的文件名是正常的。                    Response.AppendHeader("Content-Disposition", "attachment;filename=" + newfileName);//为用户保存文件是显示的名称                  //告诉客户端这个响应内容的类型为attachment 你是通过Response.AppendHeader("content-type", "attachment"); 申明的。                  Response.AppendHeader("Content-Length", fi.Length.ToString());                  Response.ContentType = "application/octet-stream";                  Response.WriteFile(newfileName);//用response来返回文件的路径                    Response.Flush();//清空response                    Response.End();                  //Response.End(); 如果抛异常的话可使用                  //HttpContext.Current.ApplicationInstance.CompleteRequest();              }              else              {                  Response.Write("<script langauge=javascript>alert(‘文件不存在!');</script>");              }