模仿php number_format函数的c# 价格转换函数

        /// <summary>
        /// 价格转换函数
        /// </summary>
        /// <param name="fot">价格字符</param>
        /// <param name="rud">保留几位</param>
        /// <param name="xNo">小数点符号</param>
        /// <param name="qNo">千位符号</param>
        /// <returns></returns>
        public static string numberFormat(string fot, int rud, char xNo, char qNo)
        {
            string number = "";
            string[] s = s = fot.Split('.');
            while (s[0].Length>3)
            {
                number = qNo + s[0].Substring(s[0].Length - 3) + number;
                s[0] = s[0].Substring(0, s[0].Length - 3);
            }

            if (s.Length == 2)
            {
                string rdWz = "";
                if (s[1].Length > rud)
                    rdWz = s[1].Substring(0, rud);
                else
                    rdWz = s[1].PadRight(rud, '0');
                number = s[0] + number + xNo + rdWz; ;
            }
            else
            {
                number = s[0] + number + xNo + "".PadRight(rud, '0');
            }
            return number;

        }

如：1000000000 输出1,000,000,000.00

随手写的，不完美的地方请提出。