C#数值笔记一

    class Program
    {
        static void Main(string[] args)
        {
            var integer = 10000;
            var decimals = 10000.12345;
            var percent = 0.12345;

            //四舍五入保留N位小数，默认保留两位小数
            Console.WriteLine("{0}.ToString(\"0\") = {1}".FormatWith(integer, integer.ToString("0.00")));    //10000.00
            Console.WriteLine("{0}.ToString(\"0.00\") = {1}".FormatWith(integer, integer.ToString("0.00")));    //10000.00
            Console.WriteLine("{0}.ToString(\"0.00\") = {1}".FormatWith(decimals, decimals.ToString("0.00")));   //10000.12
            Console.WriteLine("{0}.ToString(\"0.00000\") = {1}".FormatWith(decimals, decimals.ToString("0.0000"))); //10000.1235
            Console.WriteLine();

            //四舍五入保留N位小数，默认保留两位小数
            Console.WriteLine("{0}.ToString(\"F\") = {1}".FormatWith(integer, integer.ToString("F")));    //10000.00
            Console.WriteLine("{0}.ToString(\"F2\") = {1}".FormatWith(integer, integer.ToString("F2")));    //10000.00
            Console.WriteLine("{0}.ToString(\"F2\") = {1}".FormatWith(decimals, decimals.ToString("F2"))); //10000.12
            Console.WriteLine("{0}.ToString(\"F4\") = {1}".FormatWith(decimals, decimals.ToString("F4"))); //10000.1235
            Console.WriteLine();

            //以千分位分隔数字，四舍五入保留N位小数，默认保留两位小数
            Console.WriteLine("{0}.ToString(\"N\") = {1}".FormatWith(integer, integer.ToString("N")));    //10,000.00
            Console.WriteLine("{0}.ToString(\"N2\") = {1}".FormatWith(integer, integer.ToString("N2")));    //10,000.00
            Console.WriteLine("{0}.ToString(\"N2\") = {1}".FormatWith(decimals, decimals.ToString("N2"))); //10,000.12
            Console.WriteLine("{0}.ToString(\"N4\") = {1}".FormatWith(decimals, decimals.ToString("N4"))); //10,000.1235

            //以百分比表示数字，四舍五入保留N位小数，默认保留两位小数
            Console.WriteLine("{0}.ToString(\"P\") = {1}".FormatWith(percent, percent.ToString("P")));    //12.35%
            Console.WriteLine("{0}.ToString(\"P1\") = {1}".FormatWith(percent, percent.ToString("P1")));    //12.3%
            Console.WriteLine("{0}.ToString(\"P2\") = {1}".FormatWith(percent, percent.ToString("P2")));    //12.35%

            Console.ReadKey();
        }
    }