/// <summary>

        /// 防止开放重定向

        /// </summary>

        /// <param name="url"></param>

        /// <returns></returns>

        public static bool IsLocalUrl(string url)

        {

            if (string.IsNullOrEmpty(url))

                return false;

            bool result = ((url[0] == '/' && (url.Length == 1 || (url[1] != '/' && url[1] != '\\'))) || (url.Length > 1 && url[0] == '~' && url[1] == '/'));

            //绝对路径

            if (!result && (url.StartsWith("http:", StringComparison.OrdinalIgnoreCase) || url.StartsWith("https:", StringComparison.OrdinalIgnoreCase)))

            {

                Uri absoluteUri;

                if (Uri.TryCreate(url, UriKind.Absolute, out absoluteUri))

                {

                    return String.Equals(HttpContext.Current.Request.Url.Host, absoluteUri.Host, StringComparison.OrdinalIgnoreCase);

                }

            }

            return result;

            //来自Mvc中的UrlHelper.IsLocalUrl,只能判断相对路径

            //!string.IsNullOrEmpty(url) && ((url[0] == '/' && (url.Length == 1 || (url[1] != '/' && url[1] != '\\'))) || (url.Length > 1 && url[0] == '~' && url[1] == '/'));

        }

public void Login(string userName,string password, string returnUrl)

{

//logic code

//validate userName password

if (!string.IsNullOrEmpty(returnUrl) && Url.IsLocalUrl(returnUrl) )

{

return Response.Redirect(returnUrl);

}

return Response.Redirect("/");

}