Como acessar os serviços do WCF com contratos de resposta/solicitação e unidirecionais

Artigo
04/07/2023

Os procedimentos a seguir descrevem como acessar um serviço WCF (Windows Communication Foundation) que define um contrato unidirecional e um contrato de solicitação-resposta e que não usa o padrão de comunicação duplex.

Para definir o serviço

Declare o contrato de serviço. As operações que precisam ser unidirecionais precisam ter IsOneWay definido como true dentro do OperationContractAttribute. O código a seguir declara o contrato IOneWayCalculator que tem operações unidirecionais para Add, Subtract, Multiply e Divide. Ele também define uma operação de resposta de solicitação chamada SayHello.

[ServiceContract(Namespace = "http://Microsoft.ServiceModel.Samples")]  
public interface IOneWayCalculator  
{  
    [OperationContract(IsOneWay = true)]  
    void Add(double n1, double n2);  
    [OperationContract(IsOneWay = true)]  
    void Subtract(double n1, double n2);  
    [OperationContract(IsOneWay = true)]  
    void Multiply(double n1, double n2);  
    [OperationContract(IsOneWay = true)]  
    void Divide(double n1, double n2);  
    [OperationContract]  
    string SayHello(string name);  
}

Implemente o contrato de serviço. O código a seguir implementa a interface IOnewayCalculator.

[ServiceBehavior(ConcurrencyMode = ConcurrencyMode.Multiple, InstanceContextMode = InstanceContextMode.PerCall)]  
public class CalculatorService : IOneWayCalculator  
{  
    public void Add(double n1, double n2)  
    {  
       double result = n1 + n2;  
       Console.WriteLine("Add({0},{1}) = {2} ", n1, n2, result);  
    }  

    public void Subtract(double n1, double n2)  
    {  
       double result = n1 - n2;  
       Console.WriteLine("Subtract({0},{1}) = {2}", n1, n2, result);  
    }  

    public void Multiply(double n1, double n2)  
    {  
        double result = n1 * n2;  
        Console.WriteLine("Multiply({0},{1}) = {2}", n1, n2, result);  
    }  

    public void Divide(double n1, double n2)  
    {  
        double result = n1 / n2;  
        Console.WriteLine("Divide({0},{1}) = {2}", n1, n2, result);  
    }  

    public string SayHello(string name)  
    {  
        Console.WriteLine("SayHello({0})", name);  
        return "Hello " + name;  
    }  
}

Hospede o serviço em um aplicativo de console. O código a seguir mostra como hospedar o serviço.

// Host the service within this EXE console application.  
public static void Main()  
{  
   // Define the base address for the service.  
   Uri baseAddress = new Uri("http://localhost:8000/servicemodelsamples/service");  

   // Create a ServiceHost for the CalculatorService type and provide the base address.  
   using (ServiceHost serviceHost = new ServiceHost(typeof(CalculatorService), baseAddress))  
   {  
        // Add an endpoint using the IOneWayCalculator contract and the WSHttpBinding  
        serviceHost.AddServiceEndpoint(typeof(IOneWayCalculator), new WSHttpBinding(), "");  

      // Turn on the metadata behavior, this allows svcutil to get metadata for the service.  
      ServiceMetadataBehavior smb = (ServiceMetadataBehavior) serviceHost.Description.Behaviors.Find<ServiceMetadataBehavior>();  
      if (smb == null)  
      {  
            smb = new ServiceMetadataBehavior();  
            smb.HttpGetEnabled = true;  
            serviceHost.Description.Behaviors.Add(smb);  
      }  

      // Open the ServiceHostBase to create listeners and start listening for messages.  
      serviceHost.Open();  

      // The service can now be accessed.  
      Console.WriteLine("The service is ready.");  
      Console.WriteLine("Press <ENTER> to terminate service.");  
      Console.WriteLine();  
      Console.ReadLine();  
    }  
}

Para acessar o serviço

Execute a Ferramenta de Utilitário de Metadados do ServiceModel (Svcutil.exe) usando o endereço do ponto de extremidade da troca de metadados para criar a classe do cliente para o serviço usando a seguinte linha de comando: Svcutil http://localhost:8000/Service. A Ferramenta de Utilitário de Metadados do ServiceModel (Svcutil.exe) gera um conjunto de interfaces e classes, conforme mostrado no código de exemplo a seguir.

[System.CodeDom.Compiler.GeneratedCodeAttribute("System.ServiceModel", "3.0.0.0")]  
[System.ServiceModel.ServiceContractAttribute(Namespace="http://Microsoft.ServiceModel.Samples", ConfigurationName="IOneWayCalculator")]  
public interface IOneWayCalculator  
{  

    [System.ServiceModel.OperationContractAttribute(IsOneWay=true, Action="http://Microsoft.ServiceModel.Samples/IOneWayCalculator/Add")]  
    void Add(double n1, double n2);  

    [System.ServiceModel.OperationContractAttribute(IsOneWay=true, Action="http://Microsoft.ServiceModel.Samples/IOneWayCalculator/Subtract")]  
    void Subtract(double n1, double n2);  

    [System.ServiceModel.OperationContractAttribute(IsOneWay=true, Action="http://Microsoft.ServiceModel.Samples/IOneWayCalculator/Multiply")]  
    void Multiply(double n1, double n2);  

    [System.ServiceModel.OperationContractAttribute(IsOneWay=true, Action="http://Microsoft.ServiceModel.Samples/IOneWayCalculator/Divide")]  
    void Divide(double n1, double n2);  

    [System.ServiceModel.OperationContractAttribute(Action="http://Microsoft.ServiceModel.Samples/IOneWayCalculator/SayHello", ReplyAction="http://Microsoft.ServiceModel.Samples/IOneWayCalculator/SayHelloResponse")]  
    string SayHello(string name);  
}  

[System.CodeDom.Compiler.GeneratedCodeAttribute("System.ServiceModel", "3.0.0.0")]  
public interface IOneWayCalculatorChannel : IOneWayCalculator, System.ServiceModel.IClientChannel  
{  
}  

[System.Diagnostics.DebuggerStepThroughAttribute()]  
[System.CodeDom.Compiler.GeneratedCodeAttribute("System.ServiceModel", "3.0.0.0")]  
public partial class OneWayCalculatorClient : System.ServiceModel.ClientBase<IOneWayCalculator>, IOneWayCalculator  
{  

    public OneWayCalculatorClient()  
    {  
    }  

    public OneWayCalculatorClient(string endpointConfigurationName) :
            base(endpointConfigurationName)  
    {  
    }  

    public OneWayCalculatorClient(string endpointConfigurationName, string remoteAddress) :
            base(endpointConfigurationName, remoteAddress)  
    {  
    }  

    public OneWayCalculatorClient(string endpointConfigurationName, System.ServiceModel.EndpointAddress remoteAddress) :
            base(endpointConfigurationName, remoteAddress)  
    {  
    }  

    public OneWayCalculatorClient(System.ServiceModel.Channels.Binding binding, System.ServiceModel.EndpointAddress remoteAddress) :
            base(binding, remoteAddress)  
    {  
    }  

    public void Add(double n1, double n2)  
    {  
        base.Channel.Add(n1, n2);  
    }  

    public void Subtract(double n1, double n2)  
    {  
        base.Channel.Subtract(n1, n2);  
    }  

    public void Multiply(double n1, double n2)  
    {  
        base.Channel.Multiply(n1, n2);  
    }  

    public void Divide(double n1, double n2)  
    {  
        base.Channel.Divide(n1, n2);  
    }  

    public string SayHello(string name)  
    {  
        return base.Channel.SayHello(name);  
    }  
}

Observe na interface IOneWayCalculator que as operações de serviço unidirecional têm o atributo IsOneWay definido como true e que a operação de serviço de solicitação-resposta tem o atributo definido como o valor padrão, false. Observe também a classe OneWayCalculatorClient. Essa é a classe que você usará para chamar o serviço.

Crie o objeto cliente.

// Create a client  
WSHttpBinding binding = new WSHttpBinding();  
EndpointAddress epAddress = new EndpointAddress("http://localhost:8000/servicemodelsamples/service");  
OneWayCalculatorClient client = new OneWayCalculatorClient(binding, epAddress);

Chame operações de serviço.

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

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

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

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

// Call the SayHello service operation  
string name = "World";  
string response = client.SayHello(name);  
Console.WriteLine("SayHello([0])", name);  
Console.WriteLine("SayHello() returned: " + response);

Feche o cliente para fechar as conexões e limpar os recursos.

//Closing the client gracefully closes the connection and cleans up resources  
client.Close();

Exemplo

Veja a seguir a listagem completa do código usado neste tópico.

// Service.cs  
using System;  
using System.Configuration;  
using System.ServiceModel;  
using System.ServiceModel.Description;  
  
namespace Microsoft.ServiceModel.Samples  
{  
    // Define a service contract.
    [ServiceContract(Namespace = "http://Microsoft.ServiceModel.Samples")]  
    public interface IOneWayCalculator  
    {  
        [OperationContract(IsOneWay = true)]  
        void Add(double n1, double n2);  
        [OperationContract(IsOneWay = true)]  
        void Subtract(double n1, double n2);  
        [OperationContract(IsOneWay = true)]  
        void Multiply(double n1, double n2);  
        [OperationContract(IsOneWay = true)]  
        void Divide(double n1, double n2);  
        [OperationContract]  
        string SayHello(string name);  
    }  
  
    // Service class which implements the service contract.  
    // Added code to write output to the console window  
    [ServiceBehavior(ConcurrencyMode = ConcurrencyMode.Multiple, InstanceContextMode = InstanceContextMode.PerCall)]  
    public class CalculatorService : IOneWayCalculator  
    {  
        public void Add(double n1, double n2)  
        {  
            double result = n1 + n2;  
            Console.WriteLine("Add({0},{1}) = {2} ", n1, n2, result);  
        }  
  
        public void Subtract(double n1, double n2)  
        {  
            double result = n1 - n2;  
            Console.WriteLine("Subtract({0},{1}) = {2}", n1, n2, result);  
        }  
  
        public void Multiply(double n1, double n2)  
        {  
            double result = n1 * n2;  
            Console.WriteLine("Multiply({0},{1}) = {2}", n1, n2, result);  
        }  
  
        public void Divide(double n1, double n2)  
        {  
            double result = n1 / n2;  
            Console.WriteLine("Divide({0},{1}) = {2}", n1, n2, result);  
        }  
  
        public string SayHello(string name)  
        {  
            Console.WriteLine("SayHello({0})", name);  
            return "Hello " + name;  
        }  
  
        // Host the service within this EXE console application.  
        public static void Main()  
        {  
            // Define the base address for the service.  
            Uri baseAddress = new Uri("http://localhost:8000/servicemodelsamples/service");  
  
            // Create a ServiceHost for the CalculatorService type and provide the base address.  
            using (ServiceHost serviceHost = new ServiceHost(typeof(CalculatorService), baseAddress))  
            {  
                // Add an endpoint using the IOneWayCalculator contract and the WSHttpBinding  
                serviceHost.AddServiceEndpoint(typeof(IOneWayCalculator), new WSHttpBinding(), "");  
  
                // Turn on the metadata behavior, this allows svcutil to get metadata for the service.  
                ServiceMetadataBehavior smb = (ServiceMetadataBehavior) serviceHost.Description.Behaviors.Find<ServiceMetadataBehavior>();  
                if (smb == null)  
                {  
                    smb = new ServiceMetadataBehavior();  
                    smb.HttpGetEnabled = true;  
                    serviceHost.Description.Behaviors.Add(smb);  
                }  
  
                // Open the ServiceHostBase to create listeners and start listening for messages.  
                serviceHost.Open();  
  
                // The service can now be accessed.  
                Console.WriteLine("The service is ready.");  
                Console.WriteLine("Press <ENTER> to terminate service.");  
                Console.WriteLine();  
                Console.ReadLine();  
            }  
        }  
    }  
}

// client.cs  
using System;  
using System.ServiceModel;  
  
namespace Microsoft.ServiceModel.Samples  
{  
    //The service contract is defined in generatedClient.cs, generated from the service by the svcutil tool.  
  
    //Client implementation code.  
    class Client  
    {  
        static void Main()  
        {  
            // Create a client  
            WSHttpBinding binding = new WSHttpBinding();  
            EndpointAddress epAddress = new EndpointAddress("http://localhost:8000/servicemodelsamples/service");  
            OneWayCalculatorClient client = new OneWayCalculatorClient(binding, epAddress);  
  
            // Call the Add service operation.  
            double value1 = 100.00D;  
            double value2 = 15.99D;  
            client.Add(value1, value2);  
            Console.WriteLine("Add({0},{1})", value1, value2);  
  
            // Call the Subtract service operation.  
            value1 = 145.00D;  
            value2 = 76.54D;  
            client.Subtract(value1, value2);  
            Console.WriteLine("Subtract({0},{1})", value1, value2);  
  
            // Call the Multiply service operation.  
            value1 = 9.00D;  
            value2 = 81.25D;  
            client.Multiply(value1, value2);  
            Console.WriteLine("Multiply({0},{1})", value1, value2);  
  
            // Call the Divide service operation.  
            value1 = 22.00D;  
            value2 = 7.00D;  
            client.Divide(value1, value2);  
            Console.WriteLine("Divide({0},{1})", value1, value2);  
  
            // Call the SayHello service operation  
            string name = "World";  
            string response = client.SayHello(name);  
            Console.WriteLine("SayHello([0])", name);  
            Console.WriteLine("SayHello() returned: " + response);  
            //Closing the client gracefully closes the connection and cleans up resources  
            client.Close();  
  
        }  
    }  
}

Confira também

Serviços unidirecionais

Compartilhar via

Como acessar os serviços do WCF com contratos de resposta/solicitação e unidirecionais

Para definir o serviço

Para acessar o serviço

Exemplo

Confira também

Recursos adicionais