zoukankan      html  css  js  c++  java
  • 文件下载

    文件下载
    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;

    double pack = 10240; //10K bytes
    //int sleep = 200; //每秒5次 即5*10K bytes每秒
    int sleep = (int)Math.Floor(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;charset=gbk";
    _Response.AddHeader(
    "Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(_fileName, System.Text.Encoding.UTF8));

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

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

    myFile.Close();
    }
    }
    catch
    {
    return false;
    }
    return true;
    }
    调用方法
    ExportExcel excel = new ExportExcel();
    string fileName = excel.Export(dt, "项目统计", DataName);
    string path = Request.PhysicalApplicationPath + "Excel\\" + fileName + ".xls";
    DownFile.ResponseFile(Page.Request, Page.Response, fileName
    + ".xls", path, 1024000);

    没搞清楚到底是什么原理,留下,等以后研究。

  • 相关阅读:
    <Graph> Topological + Undirected Graph 310 Union Find 261 + 323 + (hard)305
    <Topological Sort> ( 高频, hard) 269
    <Stack> (高频)394 ( 高频)224
    <DFS & BFS> 286 339 (BFS)364
    <Matrix> 311 378
    <Binary Search> 81 (高频)34 (很难hard, 高频)315 (hard)354
    <LinkedList> 369 (高)143 (第二遍)142 148
    <DP> (高频)139 375 374 (DP hard)312
    <BackTracking> permutation 254 47 60
    <Tree> 298 250 366 199(高频) 98(高频)
  • 原文地址:https://www.cnblogs.com/smartsky/p/1880947.html
Copyright © 2011-2022 走看看