How to Create a Windows Communication Foundation contract with an interface

1. Open Visual Studio 2005 as an administrator by right-clicking the program in the StartRun as administrator. menu and selecting

2. Create a new console application project. In the New Project dialog, select Visual BasicVisual C#, and choose the Console Application template, and name it Service. Use the default Location. or

3. Change the default Service namespace to Microsoft.ServiceModel.Samples.

4. Provide a reference to the System.ServiceModel namespace for the project: Right-click the Service project in the Solution Explorer, select The System.ServiceModelComponent Name from the .NET tab, and click OK.

Following Example:-

using System;
// Step 5: Add the using statement for the Sytem.ServiceModel namespace
using System.ServiceModel;
namespace Microsoft.ServiceModel.Samples
{
 // Step 6: Define a service contract.
 [ServiceContract(Namespace = "http://Microsoft.ServiceModel.Samples")]
 public interface ICalculator
 {
   // Step7: Create the method declaration for the contract.
   [OperationContract]
   double Add(double n1, double n2);
   [OperationContract]
   double Subtract(double n1, double n2);
   [OperationContract]
   double Multiply(double n1, double n2);
   [OperationContract]
   double Divide(double n1, double n2);
 }
}