<a href="#" onclick="javascript:window.open('DownLoad.aspx?ID=11','newwin','width=350,height=510,scrollbars=0,toolbar=0,resizable=0')">打开窗口</a> 

try
            {
                string str = "select FileContent,FileType, FileName from fileinfo where id = " + base.Request.QueryString["id"];
                SqlDataReader Dr = pubValue.DataRead(str);

                string strfilePath = "file/" + base.User.Identity.Name;
                string path = "";

                if (Dr.Read())
                {
                    string s = Dr["FileName"].ToString();
                    path = base.Server.MapPath(strfilePath + "/" + s);

                    if (File.Exists(path))
                    {
                        File.Delete(path);
                    }

                    FileStream stream = new FileStream(path, FileMode.Create);
                    stream.Write((byte[])Dr["FileContent"], 0, ((byte[])Dr["FileContent"]).Length);
                    StreamWriter writer = new StreamWriter(stream);
                    writer.WriteLine("");
                    writer.Flush();
                    writer.Close();
                    stream.Close();
                    base.Response.Write("<script>location.href='" + strfilePath + "/" + base.Server.UrlEncode(s).Replace("+", "%20") + "';</script>");
                }
            }
            catch (Exception exception)
            {
                base.Response.Write(exception.Message);
            }