Getting Started Sample

Articolo
07/03/2007

The Getting Started sample demonstrates how to implement a typical service and a typical client using Windows Communication Foundation (WCF). This sample is the basis for all other basic technology samples.

Note:
The setup procedure and build instructions for this sample are located at the end of this topic.

The service describes the operations it performs in a service contract that it exposes publicly as metadata. The service also contains the code to implement the operations.

The client contains a definition of the service contract and a proxy class for accessing the service. The proxy code is generated from the service metadata using the Service Model Metadata Utility Tool (Svcutil.exe).

On Windows Vista, the service is hosted in the Windows Process Activation Service (WAS). On Windows XP and Windows Server 2003, it is hosted by Internet Information Services (IIS) and ASP.NET. Hosting a service in IIS or WAS allows the service to be activated automatically when it is accessed for the first time.

Note:
If you would prefer to get started with a sample that hosts the service in a console application instead of IIS, see the Self-Host sample.

The service and client specify access details in configuration file settings, which provide flexibility at the time of deployment. This includes an endpoint definition that specifies an address, binding, and contract. The binding specifies transport and security details for how the service is to be accessed.

The service configures a run-time behavior to publish its metadata.

The service implements a contract that defines a request-reply communication pattern. The contract is defined by the ICalculator interface, which exposes math operations (add, subtract, multiply, and divide). The client makes requests to a given math operation and the service replies with the result. The service implements an ICalculator contract that is defined in the following code.

// Define a service contract.
[ServiceContract(Namespace="http://Microsoft.ServiceModel.Samples")]
public interface ICalculator
{
    [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);
}

The service implementation calculates and returns the appropriate result, as shown in the following example code.

// Service class that implements the service contract.
public class CalculatorService : ICalculator
{
    public double Add(double n1, double n2)
    {
        return n1 + n2;
    }
    public double Subtract(double n1, double n2)
    {
        return n1 - n2;
    }
    public double Multiply(double n1, double n2)
    {
        return n1 * n2;
    }
    public double Divide(double n1, double n2)
    {
        return n1 / n2;
    }
}

The service exposes an endpoint for communicating with the service, defined using a configuration file (Web.config), as shown in the following sample configuration.

<services>
    <service 
        name="Microsoft.ServiceModel.Samples.CalculatorService"
        behaviorConfiguration="CalculatorServiceBehavior">
        <!-- ICalculator is exposed at the base address provided by         host: https://localhost/servicemodelsamples/service.svc.  -->
       <endpoint address=""
              binding="wsHttpBinding"
              contract="Microsoft.ServiceModel.Samples.ICalculator" />
       ...
    </service>
</services>

The service exposes the endpoint at the base address provided by the IIS or WAS host. The binding is configured with a standard WSHttpBinding, which provides HTTP communication and standard Web service protocols for addressing and security. The contract is the ICalculator implemented by the service.

As configured, the service can be accessed at https://localhost/servicemodelsamples/service.svc by a client on the same machine. For clients on remote machines to access the service, a fully-qualified domain name must be specified instead of localhost.

The framework does not expose metadata by default. As such, the service turns on the ServiceMetadataBehavior and exposes a metadata exchange (MEX) endpoint at https://localhost/servicemodelsamples/service.svc/mex. The following configuration demonstrates this.

  <system.serviceModel>
    <services>
      <service 
          name="Microsoft.ServiceModel.Samples.CalculatorService"
          behaviorConfiguration="CalculatorServiceBehavior">
        ...
        <!-- the mex endpoint is explosed at         https://localhost/servicemodelsamples/service.svc/mex -->
        <endpoint address="mex"
                  binding="mexHttpBinding"
                  contract="IMetadataExchange" />
      </service>
    </services>

    <!--For debugging purposes set the includeExceptionDetailInFaults     attribute to true-->
    <behaviors>
      <serviceBehaviors>
        <behavior name="CalculatorServiceBehavior">
          <serviceMetadata httpGetEnabled="True"/>
          <serviceDebug includeExceptionDetailInFaults="False" />
        </behavior>
      </serviceBehaviors>
    </behaviors>
  </system.serviceModel>

The client communicates using a given contract type by using a client class that is generated by the Service Metadata Utility Tool (Svcutil.exe). This generated client is contained in the file generatedClient.cs or generatedClient.vb. This utility retrieves metadata for a given service and generates a client for use by the client application to communicate using a given contract type. The hosted service must be available to generate the client code, because the service is used to retrieve the updated metadata.

Run the following command from the SDK command prompt in the client directory to generate the typed proxy:

svcutil.exe /n:"http://Microsoft.ServiceModel.Samples,Microsoft.ServiceModel.Samples" https://localhost/servicemodelsamples/service.svc/mex /out:generatedClient.cs

To generate client in Visual Basic type the following from the SDK command prompt:

Svcutil.exe /n:"http://Microsoft.ServiceModel.Samples,Microsoft.ServiceModel.Samples" https://localhost/servicemodelsamples/service.svc/mex /l:vb /out:generatedClient.vb

By using the generated client, the client can access a given service endpoint by configuring the appropriate address and binding. Like the service, the client uses a configuration file (App.config) to specify the endpoint with which it wants to communicate. The client endpoint configuration consists of an absolute address for the service endpoint, the binding, and the contract, as shown in the following example.

<client>
     <endpoint
         address="https://localhost/servicemodelsamples/service.svc" 
         binding="wsHttpBinding" 
         contract=" Microsoft.ServiceModel.Samples.ICalculator" />
</client>

The client implementation instantiates the client and uses the typed interface to begin communicating with the service, as shown in the following example code.

// Create a client.
CalculatorClient client = new CalculatorClient();

// Call the Add service operation.
double value1 = 100.00D;
double value2 = 15.99D;
double result = client.Add(value1, value2);
Console.WriteLine("Add({0},{1}) = {2}", value1, value2, result);

// Call the Subtract service operation.
value1 = 145.00D;
value2 = 76.54D;
result = client.Subtract(value1, value2);
Console.WriteLine("Subtract({0},{1}) = {2}", value1, value2, result);

// Call the Multiply service operation.
value1 = 9.00D;
value2 = 81.25D;
result = client.Multiply(value1, value2);
Console.WriteLine("Multiply({0},{1}) = {2}", value1, value2, result);

// Call the Divide service operation.
value1 = 22.00D;
value2 = 7.00D;
result = client.Divide(value1, value2);
Console.WriteLine("Divide({0},{1}) = {2}", value1, value2, result);

//Closing the client releases all communication resources.
client.Close();

When you run the sample, the operation requests and responses are displayed in the client console window. Press ENTER in the client window to shut down the client.

Add(100,15.99) = 115.99
Subtract(145,76.54) = 68.46
Multiply(9,81.25) = 731.25
Divide(22,7) = 3.14285714285714

Press <ENTER> to terminate client.

The Getting Started sample shows the standard way to create a service and client. Other Basic Windows Communication Foundation Technology Samples build on this sample to demonstrate specific product features.

To set up, build, and run the sample

Ensure that you have performed the One-Time Setup Procedure for the Windows Communication Foundation Samples.
To build the C# or Visual Basic .NET edition of the solution, follow the instructions in Building the Windows Communication Foundation Samples.
To run the sample in a single- or cross-machine configuration, follow the instructions in Running the Windows Communication Foundation Samples.

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Getting Started Sample

To set up, build, and run the sample

See Also

Other Resources

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