Service Contract

         Service contract describes the operation that service provides. A Service can have more than one service contract but it should have at least one Service contract.

            

          Service Contract can be define using [Service Contract] and [Operation Contract] attribute. [Service Contract] attribute is similar to the [Web Service] attribute in the Web Service and [Operation Contract] is similar to the [Web Method] in Web Service.

• It describes the client-callable operations (functions) exposed by the service
• It maps the interface and methods of your service to a platform-independent description
• It describes message exchange patterns that the service can have with another party. Some service operations might be one-way; others might require a request-reply pattern
• It is analogous to the element in WSDL

       To create a service contract you define an interface with related methods representative of a collection of service operations, and then decorate the interface with the Service Contract Attribute to indicate it is a service contract. Methods in the interface that should be included in the service contract are decorated with the Operation Contract Attribute.

Service contract describes the operation that service provides.

     

        A Service can have more than one service contract but it should have at least one Service contract.Service Contract can be define using [Service Contract] and [Operation Contract] attribute. [Service Contract] attribute is similar to the [Web Service] attribute in the Web Service and [Operation Contract] is similar to the [Web Method] in Web Service.

• It describes the client-callable operations (functions) exposed by the service
• It maps the interface and methods of your service to a platform-independent description
• It describes message exchange patterns that the service can have with another party. Some service operations might be one-way; others might require a request-reply pattern
• It is analogous to the element in WSDL

       To create a service contract you define an interface with related methods representative of a collection of service operations, and then decorate the interface with the Service Contract Attribute to indicate it is a service contract. Methods in the interface that should be included in the service contract are decorated with the Operation Contract Attribute.
  

 [Service Contract()]

    Public interface ISimpleCalculator

    {

        [Operation Contract ()]

        int Add (int num1, int num2);

    }  

    Once we define Service contract in the interface, we can create implement class for this interface.

Public class SimpleCalculator: IsimpleCalculator

 {

     Public int Add (int num1, int num2)

        {

            Return num1 + num2;

        } 

    }

     Without creating the interface, we can also directly created the service by placing Contract in the implemented class. But it is not good practice of creating the service

[Service Contract ()]

 Public class SimpleCalculator

 {

    [Operation Contract ()]

    Public int Add (int num1, int num2)

    {

         Return num1 + num2;

      } 

   }