c#实现高精度四舍五入

/// <summary>
        /// 實現數據的四捨五入
        /// </summary>
        /// <param name="colValue">四捨五入的值</param>
        /// <param name="dataScale">小數點位數</param>
        /// <returns></returns>
        private static string DataRound(double colValue, int dataScale)
        {
            string res = string.Empty;
            //實現四捨五入
            colValue = Math.Round(colValue, Convert.ToInt32(dataScale), MidpointRounding.AwayFromZero);
            res = colValue.ToString("G");
            //按精度獲取準確值
            if (res.Split('.').Length >= 2)
            {
                if (res.Split('.')[1].Length < dataScale)
                {
                    res = res.PadRight(dataScale - res.Split('.').Length, '0');
                }
                else
                {
                    res = res.Substring(2, dataScale);
                }
            }
            else
            {
                res += ".";
                res = res.PadRight(dataScale+2, '0');
            }
            return res;
        }