internal byte[] ResponseAsBytes(string RequestURL, WebResponse Response, long Length, string FileName)
        {
            string a    = null; //AttachmentName
            int    P    = 0;    //整个文件的位置指针
            int    num2 = 0;

            try
            {
                a = Response.Headers["Content-Disposition"]; //attachment
                if (a != null)
                {
                    a = a.Substring(a.LastIndexOf("filename=") + 9);
                }
                long num1  = Length; //Response.ContentLength;
                bool flag1 = false;
                if (num1 == -1)
                {
                    flag1 = true;
                    num1  = 0x10000; //64k
                }
                byte[] buffer1 = new byte[(int)num1];

                int    p = 0; //本块的位置指针
                string s = Response.Headers["Content-Range"];
                if (s != null)
                {
                    s = s.Replace("bytes ", "");
                    s = s.Substring(0, s.IndexOf("-"));
                    P = Convert.ToInt32(s);
                }
                int    num3 = 0;
                Stream S    = Response.GetResponseStream();
                do
                {
                    num2  = S.Read(buffer1, num3, ((int)num1) - num3);
                    num3 += num2;
                    if (flag1 && (num3 == num1))
                    {
                        num1 += 0x10000;
                        byte[] buffer2 = new byte[(int)num1];
                        Buffer.BlockCopy(buffer1, 0, buffer2, 0, num3);
                        buffer1 = buffer2;
                    }
                    //    lock (_SyncLockObject)
                    //    {
                    //     this._bytes += num2;
                    //    }
                    if (num2 > 0)
                    {
                        if (this.DataReceive != null)
                        {
                            byte[] buffer = new byte[num2];
                            Buffer.BlockCopy(buffer1, p, buffer, 0, buffer.Length);
                            DownLoadState     dls  = new DownLoadState(RequestURL, Response.ResponseUri.AbsolutePath, FileName, a, P, num2, buffer);
                            DownLoadEventArgs dlea = new DownLoadEventArgs(dls);
                            //触发事件
                            this.OnDataReceive(dlea);
                            //System.Threading.Thread.Sleep(100);
                        }
                        p += num2; //本块的位置指针
                        P += num2; //整个文件的位置指针
                    }
                    else
                    {
                        break;
                    }
                }while (num2 != 0);
                S.Close();
                S = null;
                if (flag1)
                {
                    byte[] buffer3 = new byte[num3];
                    Buffer.BlockCopy(buffer1, 0, buffer3, 0, num3);
                    buffer1 = buffer3;
                }
                return(buffer1);
            }
            catch (Exception e)
            {
                ExceptionActions ea = ExceptionActions.Throw;
                if (this.ExceptionOccurrs != null)
                {
                    DownLoadState      x   = new DownLoadState(RequestURL, Response.ResponseUri.AbsolutePath, FileName, a, P, num2);
                    ExceptionEventArgs eea = new ExceptionEventArgs(e, x);
                    ExceptionOccurrs(this, eea);
                    ea = eea.ExceptionAction;
                }
                if (ea == ExceptionActions.Throw)
                {
                    if (!(e is WebException) && !(e is SecurityException))
                    {
                        throw new WebException("net_webclient", e);
                    }
                    throw;
                }
                return(null);
            }
        }
        /// <summary>
        /// 分块下载文件
        /// </summary>
        /// <param name="Address">URL 地址</param>
        /// <param name="FileName">保存到本地的路径文件名</param>
        /// <param name="ChunksCount">块数,线程数</param>
        public void DownloadFile(string Address, string FileName, int ChunksCount)
        {
            int             p = 0; // position
            int             s = 0; // chunk size
            string          a = null;
            HttpWebRequest  hwrq;
            HttpWebResponse hwrp = null;

            try
            {
                hwrq = (HttpWebRequest)WebRequest.Create(this.GetUri(Address));
                hwrp = (HttpWebResponse)hwrq.GetResponse();
                long L = hwrp.ContentLength;
                hwrq.Credentials = this.m_credentials;
                L = ((L == -1) || (L > 0x7fffffff)) ? ((long)0x7fffffff) : L; //Int32.MaxValue 该常数的值为 2,147,483,647; 即十六进制的 0x7FFFFFFF
                int l = (int)L;
                this._FileLength = l;
                //    在本地预定空间(竟然在多线程下不用先预定空间)
                //    FileStream sw = new FileStream(FileName, FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.ReadWrite);
                //    sw.Write(new byte[l], 0, l);
                //    sw.Close();
                //    sw = null;
                bool b = (hwrp.Headers["Accept-Ranges"] != null & hwrp.Headers["Accept-Ranges"] == "bytes");
                a = hwrp.Headers["Content-Disposition"]; //attachment
                if (a != null)
                {
                    a = a.Substring(a.LastIndexOf("filename=") + 9);
                }
                else
                {
                    a = FileName;
                }
                int ss = s;
                if (b)
                {
                    s = l / ChunksCount;
                    if (s < 2 * 64 * 1024) //块大小至少为 128 K 字节
                    {
                        s = 2 * 64 * 1024;
                    }
                    ss = s;
                    int i = 0;
                    while (l > s)
                    {
                        l -= s;
                        if (l < s)
                        {
                            s += l;
                        }
                        if (i++ > 0)
                        {
                            DownLoadState x = new DownLoadState(Address, hwrp.ResponseUri.AbsolutePath, FileName, a, p, s, new ThreadCallbackHandler(this.DownloadFileChunk));
                            //       单线程下载
                            //       x.StartDownloadFileChunk();
                            x.httpWebClient = this;
                            //多线程下载
                            Thread t = new Thread(new ThreadStart(x.StartDownloadFileChunk));
                            //this.OnThreadProcess(t);
                            t.Start();
                        }
                        p += s;
                    }
                    s = ss;
                    byte[] buffer = this.ResponseAsBytes(Address, hwrp, s, FileName);
                    this.OnThreadProcess(Thread.CurrentThread);
                    //    lock (_SyncLockObject)
                    //    {
                    //     this._Bytes += buffer.Length;
                    //    }
                }
            }
            catch (Exception e)
            {
                ExceptionActions ea = ExceptionActions.Throw;
                if (this.ExceptionOccurrs != null)
                {
                    DownLoadState      x   = new DownLoadState(Address, hwrp.ResponseUri.AbsolutePath, FileName, a, p, s);
                    ExceptionEventArgs eea = new ExceptionEventArgs(e, x);
                    ExceptionOccurrs(this, eea);
                    ea = eea.ExceptionAction;
                }
                if (ea == ExceptionActions.Throw)
                {
                    if (!(e is WebException) && !(e is SecurityException))
                    {
                        throw new WebException("net_webclient", e);
                    }
                    throw;
                }
            }
        }