ASP.NET文件下载

        protected void Button1_Click(object sender, EventArgs e)

        {

            /*

            微软为Response对象提供了一个新的方法TransmitFile来解决使用Response.BinaryWrite

            下载超过400mb的文件时导致Aspnet_wp.exe进程回收而无法成功下载的问题。

            代码如下：

            */



            Response.ContentType = "application/x-zip-compressed";

            Response.AddHeader("Content-Disposition", "attachment;filename=z.zip");

            string filename = Server.MapPath("DownLoad/aaa.zip");

            Response.TransmitFile(filename);

        }



        //WriteFile实现下载

        protected void Button2_Click(object sender, EventArgs e)

        {

            /*

            using System.IO;

    

            */

            string fileName = "aaa.zip";//客户端保存的文件名

            string filePath = Server.MapPath("DownLoad/aaa.zip");//路径



            FileInfo fileInfo = new FileInfo(filePath);

            Response.Clear();

            Response.ClearContent();

            Response.ClearHeaders();

            Response.AddHeader("Content-Disposition", "attachment;filename=" + fileName);

            Response.AddHeader("Content-Length", fileInfo.Length.ToString());

            Response.AddHeader("Content-Transfer-Encoding", "binary");

            Response.ContentType = "application/octet-stream";

            Response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");

            Response.WriteFile(fileInfo.FullName);

            Response.Flush();

            Response.End();

        }



        //WriteFile分块下载

        protected void Button3_Click(object sender, EventArgs e)

        {



            string fileName = "aaa.zip";//客户端保存的文件名

            string filePath = Server.MapPath("DownLoad/aaa.zip");//路径



            System.IO.FileInfo fileInfo = new System.IO.FileInfo(filePath);



            if (fileInfo.Exists == true)

            {

                const long ChunkSize = 102400;//100K 每次读取文件，只读取100Ｋ，这样可以缓解服务器的压力

                byte[] buffer = new byte[ChunkSize];



                Response.Clear();

                System.IO.FileStream iStream = System.IO.File.OpenRead(filePath);

                long dataLengthToRead = iStream.Length;//获取下载的文件总大小

                Response.ContentType = "application/octet-stream";

                Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName));

                while (dataLengthToRead > 0 && Response.IsClientConnected)

                {

                    int lengthRead = iStream.Read(buffer, 0, Convert.ToInt32(ChunkSize));//读取的大小

                    Response.OutputStream.Write(buffer, 0, lengthRead);

                    Response.Flush();

                    dataLengthToRead = dataLengthToRead - lengthRead;

                }

                Response.Close();

            }

        }



        //流方式下载

        protected void Button4_Click(object sender, EventArgs e)

        {

            string fileName = "aaa.zip";//客户端保存的文件名

            string filePath = Server.MapPath("DownLoad/aaa.zip");//路径



            //以字符流的形式下载文件 需要使用FileAccess.Read，不然第二次会锁定文件无法打开

            FileStream fs = new FileStream(filePath, FileMode.Open,FileAccess.Read);

            byte[] bytes = new byte[(int)fs.Length];

            fs.Read(bytes, 0, bytes.Length);

            fs.Close();

            Response.ContentType = "application/octet-stream";

            //通知浏览器下载文件而不是打开

            Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));

            Response.BinaryWrite(bytes);

            Response.Flush();

            Response.End();



        }