WCF services are used to perform functionality that are commonly needed by our web applications. Like we need payment gateway integration in most of our websites so We will create a service for that. Lets see the example:

 [ServiceContract]

    public interface ICalculator

    {

       [OperationContract]

       double AddNumbers(double number1, double number2);

       [OperationContract]

       double SubstractNumbers(double number1, double number2);

       [OperationContract]

       double MultiplyNumbers(double number1, double number2);

       [OperationContract]

       double DivisionNumbers(double number1, double number2);

In WCF service first we have service contract which is the name of service we are making for our application then there is Operation Contract in which the functions needs to be defined. After that we will create a class where this services gets implemented by inheriting the interface.

public double AddNumbers(double number1, double number2)

        {

            double result = number1 + number2;

            return result;

        }


        public double SubstractNumbers(double number1, double number2)

        {

            double result = number1 - number2;

            return result;

        }

        public double MultiplyNumbers(double number1, double number2)

        {

            double result = number1 * number2;

            return result;

        }

        public double DivisionNumbers(double number1, double number2)

        {

            double result = number1 / number2;

            return result;

        }