For example we are an account holder of a bank, and we have permission to access all information, like other account holder’s details, bank deposited details and etc. think what happens if bank provide all accessibly to account user…….

 Through delegate we provide limited accessibility to user.

Delegate in technical Word …

• Delegate is a keyword that behaves runtime as a class.
• Class’s object has reference of a class, but delegate’s object has reference of a function.
• Through delegate we can break accessibility of all function.
• Through delegate we can save time.
• Through delegate we can achieve dynamic method invocation.
• Through delegate we called planed function.
• It absolution support type softy.
• Delegate is similar function pointer in c.
• Delegate’s object data type not fixed.
• Through delegate object we can call any function from any class but both data type and signature must be same.
• Using delegate we make dynamic object.
• Through delegate we achieve pure encapsulation.
• Simple class provides us synchronous call back. That means a class function can’t execute parallel. In other words, till one function execution not completed then we can’t call another function but delegate achieve it Asynchronous call back.
• Delegate class is independent to any class means we can declare the delegate either inside the class or outside the class.

Example

delegate int ptr();
 
    class A
    {
        public int show()
        {
            return 12;
        }
    }
 
    class B
    {
        public int display()
        {
            return 15;
        }
    }
 
 
    class Program
    {
        static void Main(string[] args)
        {
            A a = new A();
            ptr k = new ptr(a.show);
            Console.WriteLine(k());
            Console.ReadLine();
        }
    }

Output

22

    delegate int ptr();
 
    class A
    {
        public int show()
        {
            return 12;
        }
    }
 
    class B
    {
        public int display()
        {
            return 15;
        }
    }
 
 
    class Program
    {
        static void Main(string[] args)
        {
            //A a = new A();
            //ptr k = new ptr(a.show);
            //Console.WriteLine(k());
 
            B b = new B();
            ptr k = new ptr(b.display);
            Console.WriteLine(k());
            Console.ReadLine();
        }
    } 

Outout

15