c# - 如何为没有SVC文件的自托管WCF服务指定ServiceHostFactory

我的应用程序作为Windows服务运行。它使用以下帮助器方法动态创建WCF服务：

    public static void StartWebService(string webServiceName, Type serviceContractType, Type serviceImplementationType)
    {
        if (string.IsNullOrEmpty(webServiceName)) return;

        var baseAddress = GetWebServiceAddress(webServiceName);
        var baseUri = new Uri(baseAddress);

        lock (RunningWebServices)
        {
            if (RunningWebServices.ContainsKey(webServiceName))
                return;

            var webServiceHost = new ServiceHost(serviceImplementationType, baseUri);

            var serviceBehaviour = new ServiceMetadataBehavior() { HttpGetEnabled = true };
            webServiceHost.Description.Behaviors.Add(serviceBehaviour);
            webServiceHost.AddServiceEndpoint(typeof(IMetadataExchange), MetadataExchangeBindings.CreateMexHttpBinding(), "mex");

            var httpBinding = new BasicHttpBinding();
            webServiceHost.AddServiceEndpoint(serviceContractType, httpBinding, baseAddress);
            webServiceHost.Open();

            RunningWebServices.Add(webServiceName, webServiceHost);
        }
    }

这些服务没有.svc文件。还要清楚的是，这些是自托管服务，不是在iis下运行的，而是在was（windows激活服务）下运行的。
现在我想控制实现类是如何实例化的。听起来这是可以做到的。但是，我找到的所有关于这方面的文章都说，指定要使用的工厂的方法是将类型名放在.svc文件的@servicehost指令中。我没有这个文件！
在was下没有运行svc文件的情况下，有没有办法为wcf服务使用我自己的servicehost工厂？
更新以下答案
这是我的新助手方法，包含了Carlos的解

    public static void StartWebService(string webServiceName, Type serviceContractType, Type serviceImplementationType)
    {
        if (string.IsNullOrEmpty(webServiceName)) return;

        var baseAddress = GetWebServiceAddress(webServiceName);
        var baseUri = new Uri(baseAddress);

        lock (RunningWebServices)
        {
            if (RunningWebServices.ContainsKey(webServiceName))
                return;

            var webServiceHost = new ServiceHost(serviceImplementationType, baseUri);

            webServiceHost.Description.Behaviors.Add(new ServiceMetadataBehavior() { HttpGetEnabled = true });
            webServiceHost.Description.Behaviors.Add(new CustomWebServiceBehavior());

            webServiceHost.AddServiceEndpoint(typeof(IMetadataExchange), MetadataExchangeBindings.CreateMexHttpBinding(), "mex");
            webServiceHost.AddServiceEndpoint(serviceContractType, new BasicHttpBinding(), baseAddress);

            webServiceHost.Open();

            RunningWebServices.Add(webServiceName, webServiceHost);
        }
    }

internal class CustomWebServiceBehavior : IServiceBehavior, IInstanceProvider
{
    public void AddBindingParameters(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase, Collection<ServiceEndpoint> endpoints, BindingParameterCollection bindingParameters)
    {
    }

    public void ApplyDispatchBehavior(ServiceDescription serviceDescription, ServiceHostBase serviceHost)
    {
        foreach (ChannelDispatcher cd in serviceHost.ChannelDispatchers)
        {
            foreach (EndpointDispatcher ed in cd.Endpoints)
            {
                ed.DispatchRuntime.InstanceProvider = this;
            }
        }
    }

    public void Validate(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
    {
    }

    public object GetInstance(InstanceContext instanceContext, Message message)
    {
        return this.GetInstance(instanceContext);
    }

    public object GetInstance(InstanceContext instanceContext)
    {
        return // this is where I use my factory;
    }

    public void ReleaseInstance(InstanceContext instanceContext, object instance)
    {
    }
}

最佳答案

您不需要服务宿主工厂来控制服务实现类的实例化方式—您需要的是通过使用自定义服务行为将IInstanceProvider添加到调度运行时。在http://blogs.msdn.com/b/carlosfigueira/archive/2011/05/31/wcf-extensibility-iinstanceprovider.aspx上的博客文章有很多关于如何实现这一点的细节。例如，下面的SSCCE显示了如何使用实例提供程序的示例（对于在wcf中没有默认构造函数的服务，因此在没有实例提供程序的情况下不能直接使用它）

public class StackOverflow_29825519
{
    [ServiceContract]
    public interface ITest
    {
        [OperationContract]
        string WhoAmI();
    }
    public class Service : ITest
    {
        string name;

        public Service(string name)
        {
            this.name = name;
        }

        public string WhoAmI()
        {
            return this.name;
        }
    }
    class MyBehavior : IServiceBehavior, IInstanceProvider
    {
        public void AddBindingParameters(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase, Collection<ServiceEndpoint> endpoints, BindingParameterCollection bindingParameters)
        {
        }

        public void ApplyDispatchBehavior(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
        {
            foreach (ChannelDispatcher cd in serviceHostBase.ChannelDispatchers)
            {
                foreach (EndpointDispatcher ed in cd.Endpoints)
                {
                    ed.DispatchRuntime.InstanceProvider = this;
                }
            }
        }

        public void Validate(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
        {
        }

        public object GetInstance(InstanceContext instanceContext, Message message)
        {
            return this.GetInstance(instanceContext);
        }

        public object GetInstance(InstanceContext instanceContext)
        {
            return new Service("John Doe");
        }

        public void ReleaseInstance(InstanceContext instanceContext, object instance)
        {
        }
    }
    public static void Test()
    {
        string baseAddress = "http://" + Environment.MachineName + ":8000/Service";
        ServiceHost host = new ServiceHost(typeof(Service), new Uri(baseAddress));
        host.AddServiceEndpoint(typeof(ITest), new BasicHttpBinding(), "");
        host.Description.Behaviors.Add(new MyBehavior());
        host.Open();
        Console.WriteLine("Host opened");

        ChannelFactory<ITest> factory = new ChannelFactory<ITest>(new BasicHttpBinding(), new EndpointAddress(baseAddress));
        ITest proxy = factory.CreateChannel();
        Console.WriteLine("WhoAmI: {0}", proxy.WhoAmI());

        ((IClientChannel)proxy).Close();
        factory.Close();

        Console.Write("Press ENTER to close the host");
        Console.ReadLine();
        host.Close();
    }
}

关于c# - 如何为没有SVC文件的自托管WCF服务指定ServiceHostFactory，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/29825519/