日期:2014-05-18  浏览次数:20462 次

ASP.NET下载大文件方式处理
ASP.NET下载大文件 是以什么方式控制比较合理。

TransmitFile,,WriteFile, 流方式……

不让用户知道下载路径是什么

------解决方案--------------------
前面看错了以为是上传文件,下载大文件当然是文件流,你也只能得到文件流。
------解决方案--------------------
C# code

using System;
using System.Collections;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.Xml.Linq;

namespace Asiastar.NR.Ajax
{
    /// <summary>
    /// $codebehindclassname$ 的摘要说明
    /// </summary>
    [WebService(Namespace = "http://tempuri.org/")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    public class Handler1 : IHttpHandler
    {

        public void ProcessRequest(HttpContext context)
        {
            context.Response.ContentType = "text/plain";

            string id = context.Request["id"].ToString();//获取资源的编号
            System.IO.Stream iStream = null;
            byte[] buffer = new Byte[10000];
            int length;
            long dataToRead;
            NRBLL.File bf = new Asiastar.NRBLL.File();
            Guid guid = new Guid(id);
            if (bf.FN_SerchPathByFileId(guid).Tables[0].Rows[0]["FilePath"] != null)//判断数据库路径是否存在         
            {
                string filepath = bf.FN_SerchPathByFileId(guid).Tables[0].Rows[0]["FilePath"].ToString();//获取资源完整路径                   D:\资源文件\600cc139-14cf-448e-9e50-daa972d35e01.jpg
                string Oidfilename = bf.FN_SerchPathByFileId(guid).Tables[0].Rows[0]["FileNam"].ToString();//旧文件名称
                //string filename = System.IO.Path.GetFileName(filepath);//获取文件名称+后缀名            600cc139-14cf-448e-9e50-daa972d35e01.JPG
                //int index = filepath.IndexOf(".");
                //string filetype = filepath.Substring(index).ToLower();//后缀名
                //string newfilename = Oidfilename;
                //string filepath1 = bf.FN_SerchPathByFileId(guid).Tables[0].Rows[0]["FilePath"].ToString().Substring(0,filepath.Length - 8);
                try
                {
                    string fileName = HttpUtility.UrlEncode(System.Text.Encoding.UTF8.GetBytes(Oidfilename));//解码(注意这里2层解码)
                    Oidfilename = Oidfilename.Replace("+", "%20");  //将“+”替换成“空格”
                    iStream = new System.IO.FileStream(filepath, System.IO.FileMode.Open, System.IO.FileAccess.Read, System.IO.FileShare.Read);
                    dataToRead = iStream.Length;
                    context.Response.ContentType = "application/octet-stream";
                    context.Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(Oidfilename, System.Text.Encoding.UTF8));  //下载的时候下载原来的文件名称
                    while (dataToRead > 0)
                    {
                        if (context.Response.IsClientConnected)
                        {
                            length = iStream.Read(buffer, 0, 10000);
                            context.Response.OutputStream.Write(buffer, 0, length);
                            context.Response.Flush();
                            buffer = new Byte[10000];
                            dataToRead = dataToRead - length;
                        }
                        else
                        {
                            dataToRead = -1;
                        }
                    }

                }
                catch (Exception ex)
                {
                    NR.Error.Log.LogType(ex.ToString());
                }
                finally
                {
                    if (iStream != null)
                    {
                        iStream.Close();
                    }
                }
            }
            else
            {
                NR.Error.Log.LogType("找不到文