基于Winform、WPF等的客户端文件下载

　　　　/// <summary>
      /// 下载文件
      /// </summary>
      /// <param name="URL">下载文件地址</param>
      /// <param name="Filename">下载后的存放地址</param>
      public void DownloadFile(string URL, string filename)
      {
         try
         {
            System.Net.HttpWebRequest Myrq = (System.Net.HttpWebRequest)System.Net.HttpWebRequest.Create(URL);
            System.Net.HttpWebResponse myrp = (System.Net.HttpWebResponse)Myrq.GetResponse();
            long totalBytes = myrp.ContentLength;

            System.IO.Stream st = myrp.GetResponseStream();
            System.IO.Stream so = new System.IO.FileStream(filename, System.IO.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;
               so.Write(by, 0, osize);

               osize = st.Read(by, 0, (int)by.Length);
            }
            so.Close();
            st.Close();
         }
         catch (System.Exception)
         {
            throw;
         }
      }

         Downloader down = new Downloader();
         down.DownloadFile("http://www.***.com/20140124.jpg", @"d:\1.jpg");