C# Asynchron call with Named Pipes in WCF
I have a WCF host created with named pipes binding:
using System;
using System.ServiceModel;
using System.ServiceModel.Description;
namespace Microsoft.ServiceModel.Samples
{
// Define a service contract.
[ServiceContract]
public interface ICalculator
{
[OperationContract]
double Add(double n1, double n2);
}
// Step 1: Create service class that implements the service contract.
public class CalculatorService : ICalculator
{
// Step 2: Implement functionality for the service operations.
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;
}
}
class Program
{
static void Main(string[] args)
{
// Step 1 of the address configuration procedure: Create a URI to serve as the base address.
Uri baseAddress = new Uri("net.pipe://localhost");
// Step 2 of the hosting procedure: Create ServiceHost
ServiceHost selfHost = new ServiceHost(typeof(CalculatorService), baseAddress);
try
{
selfHost.AddServiceEndpoint(
typeof(ICalculator),
new NetNamedPipeBinding(),
"Calc");
// Step 4 of the hosting procedure: Enable metadata exchange.
ServiceMetadataBehavior SMB = new ServiceMetadataBehavior();
selfHost.Description.Behaviors.Add(SMB);
selfHost.AddServiceEndpoint(typeof(IMetadataExchange),
MetadataExchangeBindings.CreateMexNamedPipeBinding(),
"mex");
// Step 5 of the hosting procedure: Start (and then stop) the service.
selfHost.Open();
Console.WriteLine("The service is ready.");
Console.WriteLine("Press <ENTER> to terminate service.");
Console.WriteLine();
Console.ReadLine();
// Close the ServiceHostBase to shutdown the service.
selfHost.Close();
}
catch (CommunicationException ce)
{
Console.WriteLine("An exception occurred: {0}", ce.Message);
selfHost.Abort();
}
}
}
}
This host starts up correct. Now, I want to be able to call the Add method asynchron. Therefore I use svcutil:
svcutil.exe /config:app.config /out:generatedProxy.cs net.pipe://localhost /a /tcv:Version35
The proxy client is generated and I use this implementation:
namespace Microsoft.ServiceModel.Samples
{
class Program
{
static void Main(string[] args)
{
CalculatorClient client = new CalculatorClient();
Console.ReadLine();
double value1 = 5;
double value2 = 3;
double result = client.Add(value1, value2);
Console.WriteLine("Add({0},{1}) = {2}", value1, value2, result);
Console.WriteLine("Now async");
value1 = 100.00D;
value2 = 15.99D;
client.AddCompleted += new EventHandler<AddCompletedEvent开发者_开发技巧Args>(AddCallback);
client.AddAsync(value1, value2);
Console.WriteLine("Add({0},{1})", value1, value2);
client.Close();
}
// Asynchronous callbacks for displaying results.
static void AddCallback(object sender, AddCompletedEventArgs e)
{
Console.WriteLine("Add Result async: {0}", e.Result);
}
}
}
When running the client I get the following exception: System.ServiceModel.CommunicationException: The server did not provide a meaningful reply The problem is that when configuring this example to an http binding everything is fine, so I guess there must be something obeyed when working with async named pipes method call?!
Thanks, Juergen
Read through
http://msdn.microsoft.com/en-us/library/ms734701(v=VS.90).aspx
http://msdn.microsoft.com/en-us/library/system.servicemodel.operationcontractattribute.asyncpattern(v=VS.90).aspx
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