Tutorial: Implement a Windows Communication Foundation service contract

This tutorial describes the second of five tasks required to create a basic Windows Communication Foundation (WCF) application. For an overview of the tutorials, see Tutorial: Get started with Windows Communication Foundation applications.

The next step for creating a WCF application is to add code to implement the WCF service interface that you created in the previous step. In this step, you create a class named CalculatorService that implements the user-defined ICalculator interface. Each method in the following code calls a calculator operation and writes text to the console to test it.

In this tutorial, you learn how to:

• Add code to implement the WCF service contract.
• Build the solution.

Add code to implement the WCF service contract

In GettingStartedLib, open the Service1.cs or Service1.vb file and replace its code with the following code:

using System;
using System.ServiceModel;

namespace GettingStartedLib
{
    public class CalculatorService : ICalculator
    {
        public double Add(double n1, double n2)
        {
            double result = n1 + n2;
            Console.WriteLine("Received Add({0},{1})", n1, n2);
            // Code added to write output to the console window.
            Console.WriteLine("Return: {0}", result);
            return result;
        }

        public double Subtract(double n1, double n2)
        {
            double result = n1 - n2;
            Console.WriteLine("Received Subtract({0},{1})", n1, n2);
            Console.WriteLine("Return: {0}", result);
            return result;
        }

        public double Multiply(double n1, double n2)
        {
            double result = n1 * n2;
            Console.WriteLine("Received Multiply({0},{1})", n1, n2);
            Console.WriteLine("Return: {0}", result);
            return result;
        }

        public double Divide(double n1, double n2)
        {
            double result = n1 / n2;
            Console.WriteLine("Received Divide({0},{1})", n1, n2);
            Console.WriteLine("Return: {0}", result);
            return result;
        }
    }
}

Imports System.ServiceModel

Namespace GettingStartedLib

    Public Class CalculatorService
        Implements ICalculator

        Public Function Add(ByVal n1 As Double, ByVal n2 As Double) As Double Implements ICalculator.Add
            Dim result As Double = n1 + n2
            ' Code added to write output to the console window.
            Console.WriteLine("Received Add({0},{1})", n1, n2)
            Console.WriteLine("Return: {0}", result)
            Return result
        End Function

        Public Function Subtract(ByVal n1 As Double, ByVal n2 As Double) As Double Implements ICalculator.Subtract
            Dim result As Double = n1 - n2
            Console.WriteLine("Received Subtract({0},{1})", n1, n2)
            Console.WriteLine("Return: {0}", result)
            Return result

        End Function

        Public Function Multiply(ByVal n1 As Double, ByVal n2 As Double) As Double Implements ICalculator.Multiply
            Dim result As Double = n1 * n2
            Console.WriteLine("Received Multiply({0},{1})", n1, n2)
            Console.WriteLine("Return: {0}", result)
            Return result

        End Function

        Public Function Divide(ByVal n1 As Double, ByVal n2 As Double) As Double Implements ICalculator.Divide
            Dim result As Double = n1 / n2
            Console.WriteLine("Received Divide({0},{1})", n1, n2)
            Console.WriteLine("Return: {0}", result)
            Return result

        End Function
    End Class
End Namespace

Edit App.config

Edit App.config in GettingStartedLib to reflect the changes you made to the code.

• For Visual C# projects:

  • Change line 14 to <service name="GettingStartedLib.CalculatorService">
  • Change line 17 to <add baseAddress = "http://localhost:8000/GettingStarted/CalculatorService" />
  • Change line 22 to <endpoint address="" binding="wsHttpBinding" contract="GettingStartedLib.ICalculator">

• For Visual Basic projects:

  • Change line 14 to <service name="GettingStartedLib.GettingStartedLib.CalculatorService">
  • Change line 17 to <add baseAddress = "http://localhost:8000/GettingStarted/CalculatorService" />
  • Change line 22 to <endpoint address="" binding="wsHttpBinding" contract="GettingStartedLib.GettingStartedLib.ICalculator">

Compile the code

Build the solution to verify there aren't any compilation errors. If you're using Visual Studio, on the Build menu select Build Solution (or press Ctrl+Shift+B).

Next steps

In this tutorial, you learned how to:

• Add code to implement the WCF service contract.
• Build the solution.

Advance to the next tutorial to learn how to run the WCF service.

Tutorial: Host and run a basic WCF service