WCF 学习笔记： ServiceHost

来源：互联网发布：unity3d ios 录屏处理编辑：程序博客网时间：2024/04/29 16:20

WCF 服务的host方式主要有两种：self-hosting，active-hosting，举个例子：前者是指将wcf service 寄宿到console application上，后者则是将wcf service部署到IIS上。至于它们的好处嘛，感觉还是根据具体的需求来选择具体的途径。

WCF service 在host之前，是可以对它进行一些修改，比如：添加behavior，endpoint。这些修改主要是用来修改Service Description类，因为service 在host的时候是需要根据该类来构建一系列的对象。

贴一段关于service description的代码

            var serviceDescription = CreateServiceDescription();            Console.WriteLine("{0, -17}: {1}", "Name", serviceDescription.Name);            Console.WriteLine("{0, -17}: {1}", "Namespace", serviceDescription.Namespace);            Console.WriteLine("{0, -17}: {1}", "ConfigurationName", serviceDescription.ConfigurationName);            Console.WriteLine("{0, -17}: {1}", "Behaviors", serviceDescription.Behaviors[0].GetType().Name);            for (int i = 1; i < serviceDescription.Behaviors.Count; i++)            {                Console.WriteLine("{0, -17}: {1}", "", serviceDescription.Behaviors[i].GetType().Name);            }            Console.WriteLine();            for (int i = 1; i <= serviceDescription.Endpoints.Count; i++)            {                ServiceEndpoint endpoint = serviceDescription.Endpoints[i - 1];                Console.WriteLine("第{0}个终结点", i);                Console.WriteLine("\t{0, -9}: {1}", "Address", endpoint.Address);                Console.WriteLine("\t{0, -9}: {1}", "Binding", endpoint.Binding);                Console.WriteLine("\t{0, -9}: {1}", "Contract", endpoint.Contract.ContractType.Name);                if (endpoint.Behaviors.Count > 0)                {                    Console.WriteLine("\t{0, -9}: {1}", "Behaviors", endpoint.Behaviors[0].GetType().Name);                }                for (int j = 1; j < endpoint.Behaviors.Count; j++)                {                    Console.WriteLine("\t{0, -9}: {1}", "", endpoint.Behaviors[j].GetType().Name);                }                Console.WriteLine();            }

        static ServiceDescription CreateServiceDescription()        {            Type serviceType=typeof(CalculatorService);            ServiceDescription description = new ServiceDescription();            description.ServiceType = serviceType;            var serviceBehaviors=(from item in serviceType.GetCustomAttributes(false)                                             where item is IServiceBehavior                                             select item as IServiceBehavior).ToArray();            Array.ForEach(serviceBehaviors,(item)=>{description.Behaviors.Add(item);});            if(description.Behaviors.Find<ServiceBehaviorAttribute>() ==null)            {                ServiceBehaviorAttribute behavior=new ServiceBehaviorAttribute();                description.Behaviors.Add(behavior);            }                        description.Name=description.Behaviors.Find<ServiceBehaviorAttribute>().Name;            description.Namespace=description.Behaviors.Find<ServiceBehaviorAttribute>().Namespace;            description.ConfigurationName = description.Behaviors.Find<ServiceBehaviorAttribute>().ConfigurationName;            //load service behaviors from configuration file            ServiceElement serviceElement = ConfigLoader.GetServiceElement(description.ConfigurationName);            if (!string.IsNullOrEmpty(serviceElement.BehaviorConfiguration))            {                ServiceBehaviorElement behaviorElement = ConfigLoader.GetServiceBehaviorElement(serviceElement.BehaviorConfiguration);                foreach (BehaviorExtensionElement extensionElemenet in behaviorElement)                {                    IServiceBehavior serviceBehavior = extensionElemenet.CreateBehavior() as IServiceBehavior;                    description.Behaviors.Add(serviceBehavior);                }            }            //add EndpointAdress from configuraiton file            foreach (ServiceEndpointElement endpointElement in serviceElement.Endpoints)            {                 description.Endpoints.Add(CreateServiceEndpoint(serviceType,endpointElement));                            }            return description;                 }

wcf service 在host的时候有2种方式来生成必须的绑定元素，1）根据配置文件生产；2）动态绑定。贴两段关于动态生成Service Endpoint 和 Service Contract 的代码：

       static ServiceEndpoint CreateServiceEndpoint(Type serviceType, ServiceEndpointElement endpointElement)        {            //创建ServiceEndpoint            EndpointAddress address = new EndpointAddress(endpointElement.Address);            Binding binding = ConfigLoader.CreateBinding(endpointElement.Binding);            ContractDescription contract = CreateContractDescription(serviceType, endpointElement.Contract);            ServiceEndpoint endpoint = new ServiceEndpoint(contract, binding, address);            //添加终结点行为            if (!string.IsNullOrEmpty(endpointElement.BehaviorConfiguration))            {                EndpointBehaviorElement behaviorElement = ConfigLoader.GetEndpointBehaviorElement(endpointElement.BehaviorConfiguration);                foreach (BehaviorExtensionElement extensionElement in behaviorElement)                {                    IEndpointBehavior endpointBehavior = (IEndpointBehavior)extensionElement.CreateBehavior();                    endpoint.Behaviors.Add(endpointBehavior);                }            }            return endpoint;        }        static ContractDescription CreateContractDescription(Type serviceType, string configurationName)        {            foreach (Type contract in serviceType.GetInterfaces())            {                ServiceContractAttribute serviceContractAttribute = contract.GetCustomAttributes(typeof(ServiceContractAttribute), false).FirstOrDefault() as ServiceContractAttribute;                if (null != serviceContractAttribute)                {                    string configName = serviceContractAttribute.ConfigurationName ?? contract.Namespace + "." + contract.Name;                    if (configurationName == configName)                    {                        return ContractDescription.GetContract(contract, serviceType);                    }                }            }            return null;        }    }

 ServiceMetadataBehavior behavior = new ServiceMetadataBehavior();                behavior.HttpGetEnabled = true;                behavior.HttpGetUrl = new Uri(host.Description.Endpoints[0].Address.Uri.ToString() + "/mex");                host.Description.Behaviors.Add(behavior);                host.AddServiceEndpoint(typeof(IMetadataExchange), MetadataExchangeBindings.CreateMexHttpBinding(), host.Description.Endpoints[0].Address.Uri.ToString() + "/mex");

关于SVC文件的Factory属性，如果我们想在激活host在svc文件中的wcf时加入些自定义逻辑，我们可以为factory属性指定一个继承servicefactoryhostbase的类，该类的首个参数为service属性。

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