c# - C# IFormatable ToString("0.0000")

Question

我有课，我想重现与ToString("0.0000")其他数字格式相关的功能。如何才能做到这一点？

Answer 1

class MyNumber : IFormattable
{
   decimal value;
   public MyNumber(decimal value)
   { this.value = value; }

   string IFormattable.ToString(string format, IFormatProvider formatProvider)
   { return value.ToString(format, formatProvider); }

   public string ToString(string format)
   { return ((IFormattable)this).ToString(format, System.Globalization.CultureInfo.CurrentCulture); }
}

class Program
{
   static void Main(string[] args)
   {
      MyNumber num = new MyNumber(3.1415926m);
      Console.WriteLine(num.ToString("0.0000"));
      Console.WriteLine("{0:0.0000}", num);
   }
}

Answer 2

正则表达式可能是你最好的选择。