C#HttpWebRequest大文件断点续传类

using System;
using System.Collections.Generic;
using System.Text;
using System.Net;
using System.IO;

namespace Thunder8
{
    public class HttpUploader
    {
        const long partLength = 1024 * 1024 * 100;
        const string succuessFlag = “1“;

        public static string Upload（string fileName string httpUrllong seekPosition）
        {
            string result = string.Empty;
            FileStream fs = File.OpenRead（fileName）;
            HttpWebRequest request = null;
            HttpWebResponse response = null;
            Stream requestStream = null;
            Stream responseStream = null;

            try
            {
                long fileLength = fs.Length;
                long endPosition = seekPosition + partLength;

                request = （HttpWebRequest）HttpWebRequest.Create（httpUrl）;
                request.Timeout = -1;
                request.ContentType = “application/octet-stream“;
                request.AddRange（（int）seekPosition）;
                requestStream = request.GetRequestStream（）;

                byte[] buffer = new byte[1024 * 10];
                fs.Seek（seekPosition SeekOrigin.Begin）;

                int readLength = fs.Read（buffer 0 buffer.Length）;
                while （seekPosition < endPosition && readLength > 0）
                {
                    requestStream.Write（buffer 0 readLength）;
                    requestStream.Flush（）;
                    seekPosition += readLength;
                    readLength = fs.Read（buffer 0 buffer.Length）;
                }

                response = （HttpWebResponse）request.GetResponse（）;