顯示下載進度條的Asp.net(C#)函數

public static void DownFile( string URL, string Filename, ProgressBar Prog )
{
  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;
  Prog.Maximum = (int)totalBytes;
  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;
    Application.DoEvents();
    so.Write(by, 0, osize);
    Prog.Value = (int)totalDownloadedByte;
    osize = st.Read(by, 0, (int)by.Length);
  }
  so.Close();
  st.Close();
            }