Himall验证Web帮助类获得表单中的值、获得上次请求的url

///

        /// 获得表单中的值
        ///

        /// 键
        /// 默认值
        ///
        public static string GetFormString(string key, string defaultValue)
        {
            string value = HttpContext.Current.Request.Form[key];
            if (!string.IsNullOrWhiteSpace(value))
                return value;
            else
                return defaultValue;
        }

        ///

        /// 获得表单中的值
        ///

        /// 键
        ///
        public static string GetFormString(string key)
        {
            return GetFormString(key, "");