四舍五入,默认保留2位小数

        /// <summary>
        /// 四舍五入,默认保留2位小数
        /// </summary>
        /// <param name="value">值</param>
        /// <param name="decimals">保留小数位数,默认2</param>
        /// <returns></returns>
        public static decimal RoundPoint(decimal? value, int decimals = 2)
        {
            var vResult = value.GetValueOrDefault(0);
            return Math.Round(vResult, decimals);
        }