asp.net 瀏覽器下載文件的四種方式

      // 方法一：TransmitFile實現下載
        protected void Button1_Click(object sender, EventArgs e)
        {
            Response.ContentType = "application/x-zip-compressed";
            Response.AddHeader("Content-Disposition", "attachment;filename=z.zip");
            string filename = Server.MapPath("DownLoad/z.zip");
            Response.TransmitFile(filename);
        } 

ontentType 屬性指定響應的 HTTP 內容類型。如果未指定 ContentType，默認為 text/HTML。

語法 Response.ContentType [= ContentType ] 參數 ContentType 描述內容類型的字符串。該字符串通常被格式化為類型/子類型，其中類型是常規內容范疇而子類為特定內容類型。

　

       // 方法二：WriteFile實現下載
        protected void Button2_Click(object sender, EventArgs e)
        {
            string fileName = "asd.txt";//客戶端保存的文件名
            string filePath = Server.MapPath("DownLoad/aaa.txt");//路徑
 
            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();
        }

　response.write的意思是返回一個消息給其它頁面也可以，當前頁面也行的。     

        // 方法三：WriteFile分塊下載
        protected void Button3_Click(object sender, EventArgs e)
        {
            string fileName = "aaa.txt";//客戶端保存的文件名
            string filePath = Server.MapPath("DownLoad/aaa.txt");//路徑
 
            System.IO.FileInfo fileInfo = new System.IO.FileInfo(filePath);
 
            if (fileInfo.Exists == true)
            {
                const long ChunkSize = 102400;//100K 每次讀取文件，只讀取100K，這樣可以緩解服務器的壓力
                byte[] buffer = new byte[ChunkSize];
 
                Response.Clear();
                System.IO.FileStream iStream = System.IO.File.OpenRead(filePath);
                long dataLengthToRead = iStream.Length;//獲取下載的文件總大小
                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));//讀取的大小
                    Response.OutputStream.Write(buffer, 0, lengthRead);
                    Response.Flush();
                    dataLengthToRead = dataLengthToRead - lengthRead;
                }
                Response.Close();
            }
        }

　　

       // 方法四：流方式下載
        protected void Button4_Click(object sender, EventArgs e)
        {
            string fileName = "aaa.txt";//客戶端保存的文件名
            string filePath = Server.MapPath("DownLoad/aaa.txt");//路徑
 
            //以字符流的形式下載文件
            FileStream fs = new FileStream(filePath, FileMode.Open);
            byte[] bytes = new byte[(int)fs.Length];
            fs.Read(bytes, 0, bytes.Length);
            fs.Close();
            Response.ContentType = "application/octet-stream";
            //通知瀏覽器下載文件而不是打開
            Response.AddHeader("Content-Disposition", "attachment;  filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));
            Response.BinaryWrite(bytes);
            Response.Flush();
            Response.End();
 
        }