asp.net mvc文件下载

一、zip打包下载

1.依赖引用：ICSharpCode.SharpZipLib

2.设定网站有单独文件服务器，网站目录下有虚拟路径FileFolder，通过虚拟路径将文件映射到文件服务器。

设定根据Guid id可以获取到所需的文件集合

/// <summary>
        /// 下载zip文件
        /// </summary>
        /// <param name="id"></param>
        public void DownloadFiles(Guid id)
        {
            var files = fileservice.GetFiles(c => c.GroupId == id).ToList();
            List<string> paths = new List<string>(files.Count);
            //数据库文件存储示例：FileFolderfile/20161215170146_9767.pdf
            string savePath = HttpContext.Server.MapPath(@"~FileFolder");
            foreach (var file in files)
            {
                //验证文件是否存在...
                paths.Add(savePath + file.FilePath.Replace(@"FileFolder", ""));
            }
            string downloadName = "批量下载" + files[0].FileName + "等";
            HttpContext.Response.Clear();
            HttpContext.Response.AddHeader("content-disposition", "attachment; filename=" + downloadName + ".zip");
            HttpContext.Response.ContentType = "application/zip";
            HttpContext.Response.CacheControl = "Private";
            HttpContext.Response.Cache.SetExpires(DateTime.Now.AddMinutes(3));
            
            DownloadZipToBrowser(paths);
        }

        /// <summary>
        /// 下载压缩文件
        /// </summary>
        /// <param name="list"></param>
        private void DownloadZipToBrowser(IEnumerable<string> list)
        {
            ZipOutputStream zipOutputStream = null;
            var response = HttpContext.Response;
            try
            {
                byte[] buffer = new byte[4096];
                zipOutputStream = new ZipOutputStream(response.OutputStream);
                zipOutputStream.SetLevel(6); //0-9, 9 being the highest level of compression
                foreach (string fileName in list)
                {
                    string filepath = Server.MapPath(fileName);
                    Stream fs = System.IO.File.OpenRead(filepath);

                    ZipEntry entry = new ZipEntry(Path.GetFileName(filepath));
                    entry.Size = fs.Length;
                    zipOutputStream.PutNextEntry(entry);
                    int count = fs.Read(buffer, 0, buffer.Length);
                    while (count > 0)
                    {
                        zipOutputStream.Write(buffer, 0, count);
                        count = fs.Read(buffer, 0, buffer.Length);
                        if (!response.IsClientConnected)
                        {
                            break;
                        }
                        response.Flush();
                    }
                    fs.Close();
                }

            }
            catch (Exception)
            {

            }
            finally
            {
                if (zipOutputStream != null)
                    zipOutputStream.Close();
                response.Flush();
                response.End();
            }
        }

二、直接下载某一个文件：

        /// <summary>
        /// 下载文件
        /// </summary>
        /// <param name="id">FileId</param>
        public void DownloadFile(int id )
        {
            string savePath = HttpContext.Server.MapPath(@"~FileFolder");
            var fileinfo = fileservice.Find(id);
            string fullname = savePath + fileinfo.FilePath.Replace(@"FileFolder", "");
            //string fullname = fileinfo.FilePath;
            //判断文件是否存在
            if (!System.IO.File.Exists(fullname))
            {
                Response.Write("该文件不存在服务器上");
                Response.End();
                return;
            }
            FileInfo fi = new FileInfo(fullname);
            //**********处理可以解决文件类型问题
            string fileextname = fi.Extension;
            string DEFAULT_CONTENT_TYPE = "application/unknown";
            RegistryKey regkey, fileextkey;
            string filecontenttype;
            try
            {
                regkey = Registry.ClassesRoot;
                fileextkey = regkey.OpenSubKey(fileextname);
                filecontenttype = fileextkey.GetValue("Content Type", DEFAULT_CONTENT_TYPE).ToString();
            }
            catch
            {
                filecontenttype = DEFAULT_CONTENT_TYPE;
            }
            //**********end
            Response.Clear();
            Response.Charset = "utf-8";
            Response.ContentEncoding = System.Text.Encoding.UTF8;
            Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(fileinfo.FileName, System.Text.Encoding.UTF8));
            Response.ContentType = filecontenttype;
            Response.WriteFile(fullname);
            Response.End();
        }