asp.net ?获取网站根地址

 1 public static string GetSiteRoot() 2 ????????{ 3 ????????????string port = System.Web.HttpContext.Current.Request.ServerVariables["SERVER_PORT"]; 4 ????????????if (port == null || port == "80" || port == "443") 5 ????????????{ 6 ????????????????port = ""; 7 ????????????} 8 ????????????else 9 ????????????{10 ????????????????port = ":" + port;11 ????????????}12 ????????????string protocol = System.Web.HttpContext.Current.Request.ServerVariables["SERVER_PORT_SECURE"];13 ????????????if (protocol == null || protocol == "0")14 ????????????{15 ????????????????protocol = "http://";16 ????????????}17 ????????????else18 ????????????{19 ????????????????protocol = "https://";20 ????????????}21 ????????????string sOut = protocol + System.Web.HttpContext.Current.Request.ServerVariables["SERVER_NAME"] + port + System.Web.HttpContext.Current.Request.ApplicationPath;22 ????????????if (sOut.EndsWith("/"))23 ????????????{24 ????????????????sOut = sOut.Substring(0, sOut.Length - 1);25 ????????????}26 ????????????return sOut;27 ????????}