获取根目录的URL例如http://localhost:51898

　　public static string GetRootURI()

　　{

　　string AppPath = "";

　　HttpContext HttpCurrent = HttpContext.Current;

　　HttpRequest Req;

　　if (HttpCurrent != null)

　　{

　　Req = HttpCurrent.Request;

　　string UrlAuthority = Req.Url.GetLeftPart(UriPartial.Authority);

　　if (Req.ApplicationPath == null || Req.ApplicationPath == "/")

　　//直接安装在 Web 站点

　　AppPath = UrlAuthority;

　　else

　　//安装在虚拟子目录下

　　AppPath = UrlAuthority + Req.ApplicationPath;

　　}

　　return AppPath;

　　}