ASP.NET提供文件下载函数

作者：佚名 来源：月光软件站 加入时间：2005-3-1　月光软件站

// 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   // 输入参数 _Request: Page.Request对象，  _Response: Page.Response对象， _fileName: 下载文件名， _fullPath: 带文件名下载路径， _speed 每秒允许下载的字节数   // 返回是否成功   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(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((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;   } 调用例    Page.Response.Clear();           bool success = ResponseFile(Page.Request, Page.Response, "filename", @"C:\download.date", 1024000);        if(!success)     Response.Write("下载文件出错！");    Page.Response.End();