.net 下载文件

1、多文件下载并压缩

using ICSharpCode.SharpZipLib.Zip;

    public class DownLoadZip
    {
        public static void Download(IEnumerable<string> files, string zipFileName, HttpResponse response)
        {

            try
            {
                MemoryStream ms = new MemoryStream();
                byte[] buffer = null;
                using (ZipFile file = ZipFile.Create(ms))
                {
                    file.BeginUpdate();
                    file.NameTransform = new MyNameTransfom();
                    foreach (var item in files)
                    {
                        file.Add(System.Web.HttpContext.Current.Server.MapPath(item));
                    }
                    file.CommitUpdate();
                    buffer = new byte[ms.Length];
                    ms.Position = 0;
                    ms.Read(buffer, 0, buffer.Length);
                }
                response.AddHeader("content-disposition", "attachment;filename=" + HttpUtility.UrlEncode(zipFileName + ".zip", System.Text.Encoding.UTF8));
                response.BinaryWrite(buffer);
                response.Flush();
                response.End();
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
    }
    public class MyNameTransfom : ICSharpCode.SharpZipLib.Core.INameTransform
    {
        #region INameTransform 成员
        public string TransformDirectory(string name)
        {
            return null;
        }
        public string TransformFile(string name)
        {
            return Path.GetFileName(name);
        }
        #endregion
    }

2、直接下载某个文件

public static void Download1(string filePath, string fileName, HttpResponse response)
        {
            try
            {
                FileStream fs = new FileStream(System.Web.HttpContext.Current.Server.MapPath(filePath), FileMode.Open);
                byte[] bytes = new byte[(int)fs.Length];
                fs.Read(bytes, 0, bytes.Length);
                fs.Close();

                response.AddHeader("content-disposition", "attachment;filename=" +
                    HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));
                response.BinaryWrite(bytes);
                response.Flush();
                //response.End();由于代码已经过优化或者本机框架位于调用堆栈之上，无法计算表达式的值。出错
                HttpContext.Current.ApplicationInstance.CompleteRequest();
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }

string path = context.Request["path"];
            string fileName = context.Request["fileName"];
            //DownloadFile(Server.MapPath("/ShareAttachment_Attachment/" + path), name, id);
            string tempPath = AppDomain.CurrentDomain.BaseDirectory;
            try
            {

                
                tempPath = context.Request.FilePath + "00000000000" + Directory.GetParent(context.Request.FilePath);
                System.IO.FileInfo file = new System.IO.FileInfo(Directory.GetParent(context.Request.FilePath)+"\Announcement_PDF\"+path);
                context.Response.Clear();
                context.Response.Charset = "GB2312";
                context.Response.ContentEncoding = System.Text.Encoding.UTF8;
                // 添加头信息，为"文件下载/另存为"对话框指定默认文件名
                context.Response.AddHeader("Content-Disposition", "attachment; filename=" + fileName);
                // 添加头信息，指定文件大小，让浏览器能够显示下载进度
                context.Response.AddHeader("Content-Length", file.Length.ToString());
                // 指定返回的是一个不能被客户端读取的流，必须被下载
                context.Response.ContentType = "application/ms-excel";
                // 把文件流发送到客户端
                context.Response.WriteFile(file.FullName);
                // 停止页面的执行
                //Response.End();     
                HttpContext.Current.ApplicationInstance.CompleteRequest();
            }
            catch (Exception ex)
            {
                context.Response.Write("<script>alert('系统出现以下错误://n" + tempPath + ex.Message + "!//n请尽快与管理员联系.')</script>");
            }