.net下 文件下载相关函数

private void FileDownload()
    {
        String FullFileName = Server.MapPath("文件路径");
        FileInfo DownloadFile = new FileInfo(FullFileName);
        Response.Clear();
        Response.ClearHeaders();
        Response.Buffer = false;
        Response.ContentType = "application/octet-stream";
        Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(DownloadFile.FullName, System.Text.Encoding.UTF8));
        Response.AppendHeader("Content-Length", DownloadFile.Length.ToString());
        Response.WriteFile(DownloadFile.FullName);
        Response.Flush();
        Response.End();
    }

 另一个较好的:

 

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.IO;
using System.Threading;

/// <summary>
/// FileDownload 的摘要说明
/// </summary>
public class FileDownload
{
    /// <summary>
    /// 输出硬盘文件，提供下载 支持大文件、续传、速度限制、资源占用小
    /// </summary>
    /// <param name="_Request">Page.Request对象</param>
    /// <param name="_Response">Page.Response对象</param>
    /// <param name="_fileName">下载文件名</param>
    /// <param name="_fullPath">带文件名下载路径</param>
    /// <param name="_speed">每秒允许下载的字节数</param>
    /// <returns>返回是否成功</returns>
    public static bool ResponseFile(HttpRequest _Request, HttpResponse _Response, string _fileName, string _fullPath, long _speed)
    {
        try
        {
            FileStream myFile = new FileStream(_fullPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
            BinaryReader br = new BinaryReader(myFile);
            try
            {
                _Response.AddHeader("Accept-Ranges", "bytes");
                _Response.Buffer = false;
                long fileLength = myFile.Length;
                long startBytes = 0;

                int pack = 10240; //10K bytes
                //int sleep = 200;   //每秒5次   即5*10K bytes每秒
                int sleep = (int)Math.Floor((decimal)1000 * pack / _speed) + 1;
                if (_Request.Headers["Range"] != null)
                {
                    _Response.StatusCode = 206;
                    string[] range = _Request.Headers["Range"].Split(new char[] { '=', '-' });
                    startBytes = Convert.ToInt64(range[1]);
                }
                _Response.AddHeader("Content-Length", (fileLength - startBytes).ToString());
                if (startBytes != 0)
                {
                    _Response.AddHeader("Content-Range", string.Format(" bytes {0}-{1}/{2}", startBytes, fileLength - 1, fileLength));
                }
                _Response.AddHeader("Connection", "Keep-Alive");
                _Response.ContentType = "application/octet-stream";
                _Response.AddHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(_fileName, System.Text.Encoding.UTF8));

                br.BaseStream.Seek(startBytes, SeekOrigin.Begin);
                int maxCount = (int)Math.Floor((decimal)(fileLength - startBytes) / pack) + 1;

                for (int i = 0; i < maxCount; i++)
                {
                    if (_Response.IsClientConnected)
                    {
                        _Response.BinaryWrite(br.ReadBytes(pack));
                        Thread.Sleep(sleep);
                    }
                    else
                    {
                        i = maxCount;
                    }
                }
            }
            catch
            {
                return false;
            }
            finally
            {
                br.Close();
                myFile.Close();
            }
        }
        catch
        {
            return false;
        }
        return true;
    }

}

 

下载远端文件

private void BT_Update_Click(object sender, System.EventArgs e)
  {
   string slocal = Server.MapPath(".") + "/test.mdb";
   GetHttpFile("http://www.jinwensoft.com/demo/database/lawdoc.mdb", slocal);
  }

  public bool GetHttpFile(string sUrl,string sSavePath)
  {

   bool bRslt=false;

   WebResponse oWebRps=null;

   WebRequest oWebRqst=WebRequest.Create(sUrl);

   oWebRqst.Timeout=50000;

   oWebRps=oWebRqst.GetResponse();

   if(oWebRps!=null)
   {

    BinaryReader oBnyRd=new BinaryReader(oWebRps.GetResponseStream(),System.Text.Encoding.GetEncoding("GB2312"));
 
    int iLen=Convert.ToInt32(oWebRps.ContentLength);
  
    FileStream oFileStream;

   
    if(File.Exists(Request.MapPath("RecievedData.tmp")))
     oFileStream=File.OpenWrite(sSavePath);
    else
     oFileStream=File.Create(sSavePath);

    oFileStream.SetLength((Int64)iLen);

    oFileStream.Write(oBnyRd.ReadBytes(iLen),0,iLen);

    oFileStream.Close();
   }

   return bRslt;
  }