Implementation of IFormattable : IFormattable : Class C# Examples

    
using  System;

public  class  MyClass  :  IFormattable
{
        private  string  title;
        private  string[]  names;

        public  MyClass(string  title,  params  string[]  names)
        {
                this.title  =  title;
                this.names  =  names;
        }

        public  override  string  ToString()
        {
                return  ToString("G",  null);
        }

        public  string  ToString(string  format,  IFormatProvider  formatProvider)
        {
                string  result  =  null;

                if  (format  ==  null)  
                        format  =  "G";

                switch  (format.ToUpper()[0])
                {
                        case  'S':
                                result  =  "S."  ;
                                break;

                        case  'P':
                                result  =  "P.  ";
                                break;

                        case  'I':
                                result  =  "I.  ";
                                break;

                        case  'G':
                        default:
                                result  =  "G.  ";
                                break;
                }
                return  result;
        }
}

public  class  MainClass
{
        public  static  void  Main()
        {
                MyClass  person  =  new  MyClass("Mr",  "A",  "B",  "C",  "D");

                System.Console.WriteLine("Dear  {0:G},",  person);
                System.Console.WriteLine("Dear  {0:P},",  person);
                System.Console.WriteLine("Dear  {0:I},",  person);
                System.Console.WriteLine("Dear  {0},",  person);
                System.Console.WriteLine("Dear  {0:S},",  person);

        }
}