wp7之《够酷悦音播放器》 使用线程池实现多线程下载 （二）断点续传下载

  前面写到 多线程下载，没有写断点续传下载。为了完整性，补写了这篇 ；下面用代码说话

/// <summary>
        /// 下载方法(带进度条)
        /// </summary>
        /// <param name="URL">服务器URL地址</param>
        /// <param name="Filename">存放到本地的路径</param>
        /// <param name="Prog">进度条</param>
        public static void DownFile(string URL, string Filename, ProgressBar Prog)
        {

            try
            {
                HttpWebRequest Myrq = (HttpWebRequest)HttpWebRequest.Create(URL);


                HttpWebResponse myrp = (HttpWebResponse)Myrq.GetResponse();
                long totalBytes = myrp.ContentLength;
                Prog.Maximum = (int)totalBytes;
                Stream st = myrp.GetResponseStream();
                Stream so = new FileStream(Filename, FileMode.Create);
                long totalDownloadedByte = 0;
                byte[] by = new byte[1024];
                int osize = st.Read(by, 0, (int)by.Length);
                while (osize > 0)
                {
                    totalDownloadedByte = osize + totalDownloadedByte;
                    Application.DoEvents();
                    so.Write(by, 0, osize);
                    Prog.Value = (int)totalDownloadedByte;
                    osize = st.Read(by, 0, (int)by.Length);
                }
                so.Close();
                st.Close();
                MessageBox.Show("下载完毕!", "下载提示：", MessageBoxButtons.OK, MessageBoxIcon.Asterisk, MessageBoxDefaultButton.Button1);
            }

            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "提示", MessageBoxButtons.OK, MessageBoxIcon.Asterisk,
                    MessageBoxDefaultButton.Button1);
            }







方法二：

            ////打开上次下载的文件或新建文件
            //long lStartPos = 0;
            //FileStream fs;
            //if (File.Exists(Filename))
            //{
            //    fs = File.OpenWrite(Filename);
            //    lStartPos = fs.Length;
            //    fs.Seek(lStartPos, System.IO.SeekOrigin.Current); //移动文件流中的当前指针
            //}
            //else
            //{
            //    fs = new FileStream(Filename, FileMode.Create);
            //    lStartPos = 0;
            //}
            //try
            //{
            //    HttpWebRequest Myrq = (HttpWebRequest)HttpWebRequest.Create(URL);

            //    if (lStartPos > 0)
            //        Myrq.AddRange((int)lStartPos); //设置Range值

            //    HttpWebResponse myrp = (HttpWebResponse)Myrq.GetResponse();
            //    long totalBytes = myrp.ContentLength;
            //    Prog.Maximum = (int)totalBytes;
            //    Stream st = myrp.GetResponseStream();
            //    Stream so = new FileStream(Filename, FileMode.Create);
            //    long totalDownloadedByte = 0;
            //    byte[] by = new byte[1024];
            //    int osize = st.Read(by, 0, (int)by.Length);
            //    while (osize > 0)
            //    {
            //        totalDownloadedByte = osize + totalDownloadedByte;
            //        Application.DoEvents();
            //        so.Write(by, 0, osize);
            //        Prog.Value = (int)totalDownloadedByte;
            //        osize = st.Read(by, 0, (int)by.Length);
            //    }
            //    so.Close();
            //    st.Close();
            //    MessageBox.Show("下载完毕!", "下载提示：", MessageBoxButtons.OK, MessageBoxIcon.Asterisk, MessageBoxDefaultButton.Button1);
            //}

            //catch (Exception ex)
            //{
            //    MessageBox.Show(ex.Message, "提示", MessageBoxButtons.OK, MessageBoxIcon.Asterisk,
            //        MessageBoxDefaultButton.Button1);
            //}

        }