主要功能如下
/// <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>
/// <summary> /// 编 码 人:苏飞 /// 联系方式:361983679 /// 更新网站:[url=http://www.sufeinet.com/thread-655-1-1.html]http://www.sufeinet.com/thread-655-1-1.html[/url] /// </summary> using System; using System.IO; using System.Web; using System.Threading; namespace DotNet.Utilities { /// <summary> /// 文件下载帮助类 /// </summary> public class DownLoadHelper { #region ResponseFile 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> /// 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((double)(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((double)((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; } #endregion } }