C#实现有效位数，科学计数法实现代码

C#科学计数法，有效位数

代码

 /// <summary>
        /// 有效数取值带科学计数法
        /// </summary>
        /// <param name="number">浮点值</param>
        /// <param name="GYouXiao">有效位数</param>
        /// <returns>结果</returns>
        public string Significance(double number, int GYouXiao)
        {
            var A1 = number.ToString("G" + GYouXiao.ToString());
            A1 = ScientificNotation(A1, GYouXiao);
            if (!A1.Contains("×10")&& A1.Length< GYouXiao) {
                if (A1.Contains("."))
                {
                    A1 = A1.PadRight(GYouXiao+1, '0');
                }
                else
                {
                    A1 = A1 + ".";
                    A1 = A1.PadRight(GYouXiao+1, '0');
                }

            }
       
            return A1;
        }
        /// <summary>
        /// 转换科学计数法
        /// </summary>
        /// <param name="input">输入值</param>
        /// <param name="GYouXiao">有效位数</param>
        /// <returns>结果</returns>
        public static string ScientificNotation(string input,int  GYouXiao)
        {
            if (string.IsNullOrEmpty(input))
                return input;
            if (!input.ToLower().Contains("e"))
                return input;
            string[] strs = new string[] { };
            if (input.Contains("E"))
                strs = input.Split('E');
            else if (input.Contains("e"))
                strs = input.Split('e');

            if (strs.Length != 2)
                return input;
            double value;
            if (!double.TryParse(strs[0], out value))
                return input;
            if (strs[1].Length < 2)
                return input;

            string result2 = strs[1].Replace("+", "").Replace("-", "");
            string[] result2Strs = result2.Split('\r');
            result2 = result2Strs[0];
            int value2;
            if (!int.TryParse(result2, out value2))
                return input;
            string uom = string.Empty;
            if (result2Strs.Length > 1)
                uom = "\r" + result2Strs[1];
            Dictionary<char, char> ht = new Dictionary<char, char>();
            ht.Add('+', '⁺');
            ht.Add('-', '⁻');
            ht.Add('0', '⁰');
            ht.Add('1', '¹');
            ht.Add('2', '²');
            ht.Add('3', '³');
            ht.Add('4', '⁴');
            ht.Add('5', '⁵');
            ht.Add('6', '⁶');
            ht.Add('7', '⁷');
            ht.Add('8', '⁸');
            ht.Add('9', '⁹');
            string result = strs[0];
            result2 = value2.ToString();
            bool isMinus = strs[1][0] == '-';
            string minus = "";
            if (isMinus)
                minus = "⁻";
            foreach (var kv in ht)
            {
                result2 = result2.Replace(kv.Key, kv.Value);
            }
   
            return $"{result}×10{minus}{result2}{uom}";
        }

大致得思想就是通过一些特殊符号得替换来实现科学计数法。