C#数值笔记一

 1     class Program
 2     {
 3         static void Main(string[] args)
 4         {
 5             var integer = 10000;
 6             var decimals = 10000.12345;
 7             var percent = 0.12345;
 8 
 9             //四舍五入保留N位小数，默认保留两位小数
10             Console.WriteLine("{0}.ToString(\"0\") = {1}".FormatWith(integer, integer.ToString("0.00")));    //10000.00
11             Console.WriteLine("{0}.ToString(\"0.00\") = {1}".FormatWith(integer, integer.ToString("0.00")));    //10000.00
12             Console.WriteLine("{0}.ToString(\"0.00\") = {1}".FormatWith(decimals, decimals.ToString("0.00")));   //10000.12
13             Console.WriteLine("{0}.ToString(\"0.00000\") = {1}".FormatWith(decimals, decimals.ToString("0.0000"))); //10000.1235
14             Console.WriteLine();
15 
16             //四舍五入保留N位小数，默认保留两位小数
17             Console.WriteLine("{0}.ToString(\"F\") = {1}".FormatWith(integer, integer.ToString("F")));    //10000.00
18             Console.WriteLine("{0}.ToString(\"F2\") = {1}".FormatWith(integer, integer.ToString("F2")));    //10000.00
19             Console.WriteLine("{0}.ToString(\"F2\") = {1}".FormatWith(decimals, decimals.ToString("F2"))); //10000.12
20             Console.WriteLine("{0}.ToString(\"F4\") = {1}".FormatWith(decimals, decimals.ToString("F4"))); //10000.1235
21             Console.WriteLine();
22 
23             //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
24             Console.WriteLine("{0}.ToString(\"N\") = {1}".FormatWith(integer, integer.ToString("N")));    //10,000.00
25             Console.WriteLine("{0}.ToString(\"N2\") = {1}".FormatWith(integer, integer.ToString("N2")));    //10,000.00
26             Console.WriteLine("{0}.ToString(\"N2\") = {1}".FormatWith(decimals, decimals.ToString("N2"))); //10,000.12
27             Console.WriteLine("{0}.ToString(\"N4\") = {1}".FormatWith(decimals, decimals.ToString("N4"))); //10,000.1235
28 
29             //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
30             Console.WriteLine("{0}.ToString(\"P\") = {1}".FormatWith(percent, percent.ToString("P")));    //12.35%
31             Console.WriteLine("{0}.ToString(\"P1\") = {1}".FormatWith(percent, percent.ToString("P1")));    //12.3%
32             Console.WriteLine("{0}.ToString(\"P2\") = {1}".FormatWith(percent, percent.ToString("P2")));    //12.35%
33 
34             Console.ReadKey();
35         }
36     }