/// <summary>
/// 以二进制下载文件
/// </summary>
public void Download(string sFileName, string sSaveFileName)
{
     FileInfo file= new FileInfo(sFileName);

     Response.Clear();
     Response.ClearHeaders();
     Response.Buffer = false;
     Response.ContentType = "application/octet-stream";
     Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(sSaveFileName, Encoding.UTF8));
     Response.AppendHeader("Content-Length", file.Length.ToString());
     Response.WriteFile(file.FullName);
     Response.Flush();
     Response.End();
}