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  • [上传下载] C#修改DownLoadHelper上传下载帮助类 (转载)

    点击下载 DownLoadHelper.rar

    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
        }
    }
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  • 原文地址:https://www.cnblogs.com/lizeyan/p/3635401.html
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