网页文件收费下载应用实现

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通过流下载可以验证身份及收费等操作，还能避免路径外漏。

如果视频观看收费也建议使用流分段下载，这样防止文件整体被copy。爱奇艺VIP会员观看视频就是这样干的，分段观看15秒左右一段

1、文件普通下载方式：直接将<a href="XXXXXXXX/HOI.mp4"/>

2、通过一般处理程序流下载：<a href="DownLoad.ashx"/> 并没有获取到文件本身的路径

DownLoad.ashx后台代码：

    /// <summary>
    /// DownLoad 的摘要说明
    /// </summary>
    public class DownLoad : IHttpHandler
    {
        public void ProcessRequest(HttpContext context)
        {
            //创建文件读取对象 C:\Users\ykmy\Desktop\缓存\WebApplication2\WebApplication2\js\hdnj01.mp4
            using (FileStream fileReader = new FileStream(@"C:\Users\ykmy\Desktop\缓存\WebApplication2\WebApplication2\js\hdnj01.mp4", FileMode.Open, FileAccess.Read, FileShare.Read))
            {
                //(filename, FileMode.Append, FileAccess.Write,FileShare.Write))
                context.Response.ContentType = "application/octet-stream";
                context.Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(@"hdnj01.mp4", System.Text.Encoding.UTF8));
                context.Response.AddHeader("Content-Length", fileReader.Length.ToString());
                //指定文件一次读取时的字节长度
                byte[] by = new byte[1024 * 128];//控制速度[128KB]
                int count = 0;
                while (true)
                {
                    //将文件转换为二进制数据保存到内存中，同时返回读取字节的长度
                    count = fileReader.Read(by, 0, by.Length);
                    if (count == 0)//文件是否全部转换为二进制数据
                    {
                        break;
                    }
                    //将二进制数据转换为文件对象并保存到指定的物理路径中
                    context.Response.OutputStream.Write(by, 0, by.Length);
                    try
                    {
                        context.Response.Flush();
                        
                    }
                    catch
                    {
                        context.Response.Close();
                    }
                }
                context.Response.Close();
            }
        }
        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
    }

3、直接post通过网页下载 同上（属于流下载）

web：代码

                //调用
                postExcelFile(
                    PostData,
                    "/AjaxServer/XXXX.ashx?Action=XXXX&r=" + Math.random()
                );
               
            // 导出excel
            function postExcelFile(params, url) {
                //params是post请求需要的参数，url是请求url地址
                var form = document.createElement("form");
                form.style.display = "none";
                form.action = url;
                form.method = "post";
                document.body.appendChild(form);
                // 动态创建input并给value赋值
                for (var key in params) {
                    var input = document.createElement("input");
                    input.type = "hidden";
                    input.name = key;
                    input.value = params[key];
                    form.appendChild(input);
                }
                form.submit();
                form.remove();
            }

后台代码

   
                string strTime = DateTime.Now.ToString("yyyy-MM-dd_HHmmss");
                string strFile = currentContext.Server.MapPath("~/temp/check" + strTime + ".xls");
                 

                NPOIHelper.Export(dt, "", strFile);

                //-----下载 BEGIN------
                HttpContext curContext = HttpContext.Current;

                HttpContext.Current.Response.Clear();
                HttpContext.Current.Response.Buffer = true;
                HttpContext.Current.Response.Charset = "UTF-8";
                HttpContext.Current.Response.ContentEncoding = System.Text.Encoding.UTF8;
                HttpContext.Current.Response.AddHeader("Content-Disposition",
                    "attachment; filename=" + HttpUtility.UrlEncode("XXXXXXList" + strTime + ".xls", Encoding.UTF8));
                //     HttpContext.Current.Response.AddHeader("Content-Length", strFile.Length.ToString());
                HttpContext.Current.Response.ContentType = "application/ms-excel";


                using (MemoryStream ms = NPOIHelper.Export(dt, ""))
                {
                    byte[] data = ms.ToArray();
                    HttpContext.Current.Response.BinaryWrite(data);
                }
                HttpContext.Current.Response.Flush();
                
                //-----下载 END------

附目录

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.IO;
using System.Text;
using NPOI;
using NPOI.HPSF;
using NPOI.HSSF;
using NPOI.HSSF.UserModel;
using NPOI.HSSF.Util;
using NPOI.POIFS;
using NPOI.Util;

namespace BitAuto.Equipment.Framework
{

    public class NPOIHelper
    {
        /// <summary>
        /// DataTable导出到Excel文件
        /// </summary>
        /// <param name="dtSource">源DataTable</param>
        /// <param name="strHeaderText">表头文本</param>
        /// <param name="strFileName">保存位置</param>
        public static void Export(DataTable dtSource, string strHeaderText, string strFileName)
        {
            using (MemoryStream ms = Export(dtSource, strHeaderText))
            {
                using (FileStream fs = new FileStream(strFileName, FileMode.Create, FileAccess.Write))
                {
                    byte[] data = ms.ToArray();
                    fs.Write(data, 0, data.Length);
                    fs.Flush();
                }
            }
        }

        public static void CommonWebExport(DataTable dtSource, string strFileName)
        {
            HttpContext curContext = HttpContext.Current;

            HttpContext.Current.Response.Clear();
            HttpContext.Current.Response.Buffer = true;
            HttpContext.Current.Response.Charset = "UTF-8";
            HttpContext.Current.Response.ContentEncoding = System.Text.Encoding.UTF8;
            HttpContext.Current.Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(strFileName, Encoding.UTF8));

            //HttpContext.Current.Response.AddHeader("Content-Length", file.Length.ToString());

            HttpContext.Current.Response.ContentType = "application/ms-excel";
            HttpContext.Current.Response.BinaryWrite(CommonExport(dtSource).GetBuffer());

            HttpContext.Current.Response.End();

        }

        public static MemoryStream CommonExport(DataTable table)
        {
            MemoryStream ms = new MemoryStream();


            HSSFWorkbook workbook = new HSSFWorkbook();
            HSSFSheet sheet = workbook.CreateSheet();

            HSSFRow headerRow = sheet.CreateRow(0);

            // handling header.
            foreach (DataColumn column in table.Columns)
                headerRow.CreateCell(column.Ordinal).SetCellValue(column.Caption);//If Caption not set, returns the ColumnName value

            // handling value.
            int rowIndex = 1;

            foreach (DataRow row in table.Rows)
            {
                HSSFRow dataRow = sheet.CreateRow(rowIndex);

                foreach (DataColumn column in table.Columns)
                {
                    dataRow.CreateCell(column.Ordinal).SetCellValue(row[column].ToString());
                }

                rowIndex++;
            }

            workbook.Write(ms);
            ms.Flush();
            ms.Position = 0;
            return ms;
        }


        /// <summary>
        /// DataTable导出到Excel的MemoryStream
        /// </summary>
        /// <param name="dtSource">源DataTable</param>
    

本文标签： 网页文件