use of event in c# code example

Example 1: why events are usefull in c#

using System;

namespace SampleApp {
   public delegate string MyDel(string str);
	
   class EventProgram {
      event MyDel MyEvent;
		
      public EventProgram() {
         this.MyEvent += new MyDel(this.WelcomeUser);
      }
      public string WelcomeUser(string username) {
         return "Welcome " + username;
      }
      static void Main(string[] args) {
         EventProgram obj1 = new EventProgram();
         string result = obj1.MyEvent("Tutorials Point");
         Console.WriteLine(result);
      }
   }
}

Example 2: events in c# geeksforgeeks

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks; namespace event_programming{    //This is Subscriber Class    class Program    {        static void Main(string[] args)        {            AddTwoNumbers a = new AddTwoNumbers();            //Event gets binded with delegates            a.ev_OddNumber += new AddTwoNumbers.dg_OddNumber(EventMessage);            a.Add();            Console.Read();        }              //Delegates calls this method when event raised.          static void EventMessage()        {            Console.WriteLine("********Event Executed : This is Odd Number**********");        }    }    //This is Publisher Class    class AddTwoNumbers    {                public delegate void dg_OddNumber(); //Declared Delegate             public event dg_OddNumber ev_OddNumber; //Declared Events         public void Add()        {            int result;            result = 5 + 4;            Console.WriteLine(result.ToString());            //Check if result is odd number then raise event            if((result % 2 != 0) && (ev_OddNumber != null))            {                ev_OddNumber(); //Raised Event            }                  }    }}