Question

我需要在WCF服务中自定义每个方法 - 添加日志记录。

因此，我在创建服务主机时为每个操作安装了一个专用的操作行为：

public class CoreServiceHostFactory : ServiceHostFactory
{
    #region Overrides of ServiceHostFactory

    protected override ServiceHost CreateServiceHost(Type serviceType, Uri[] baseAddresses)
    {
        var host = base.CreateServiceHost(serviceType, baseAddresses);
        var operationBehavior = new WcfOperationBehavior();
        host.Description.Endpoints
            .SelectMany(e => e.Contract.Operations)
            .ForEach(o => o.Behaviors.Add(operationBehavior));

        return host;
    }

    #endregion
}

它在本地工作，但在QA中部署时失败

无法将值添加到集合中，作为集合已包含相同类型的项目： ......仅限此系列支持每种类型的一个实例。参数名称：item

web.config的相关部分是：

<services>
    <service name="DeviceServices.DeviceService" behaviorConfiguration="SLDeviceServices.ServiceBehavior">
        <endpoint address="" binding="basicHttpBinding" bindingConfiguration="StandardBindingSSL" contract="DeviceServices.IDeviceService">
        </endpoint>
        <endpoint address="" binding="basicHttpBinding" bindingConfiguration="StandardBinding" contract="DeviceServices.IDeviceService">
        </endpoint>
    </service>
    <service name="DeviceServices.DeviceServiceJSON" behaviorConfiguration="SLDeviceServices.ServiceBehavior">
        <endpoint address="" binding="webHttpBinding" bindingConfiguration="StandardBindingSSL" contract="DeviceServices.DeviceServiceJSON" behaviorConfiguration="DeviceServices.JSONDeviceServiceBehavior">
        </endpoint>
        <endpoint address="" binding="webHttpBinding" bindingConfiguration="StandardBinding" contract="DeviceServices.DeviceServiceJSON" behaviorConfiguration="DeviceServices.JSONDeviceServiceBehavior">
        </endpoint>
    </service>
</services>
<behaviors>
    <serviceBehaviors>
        <behavior name="SLDeviceServices.ServiceBehavior">
            <serviceMetadata httpsGetEnabled="false" />
            <serviceDebug includeExceptionDetailInFaults="true" />
        </behavior>
    </serviceBehaviors>
    <endpointBehaviors>
        <behavior name="DeviceServices.JSONDeviceServiceBehavior">
            <webHttp />
        </behavior>
    </endpointBehaviors>
</behaviors>

我不明白是什么问题。任何人吗？

Answer 1

我找到了根本原因。在QA中，服务有两个端点 - http和https，但两者都绑定到同一个Contract。

因此代码

host.Description.Endpoints
    .SelectMany(e => e.Contract.Operations)
    .ForEach(o => o.Behaviors.Add(operationBehavior));

两次遍历同一份合同。修复是：

host.Description.Endpoints
    .Select(e => e.Contract)
    .Distinct()
    .SelectMany(c => c.Operations)
    .ForEach(o => o.Behaviors.Add(operationBehavior));

Answer 2

访问多个服务时出现的问题。添加操作行为时需要检查重复项

host.Description.Endpoints
    .Select(e => e.Contract)
    .Distinct()
    .SelectMany(c => c.Operations)
    .ForEach(o => 
    {
       if(o.Behaviors.Any(x=> x.GetType().Equals(typeof(WcfOperationBehavior))))
       {
          o.Behaviors.Add(operationBehavior));
       }
    });

该值无法添加到集合中，因为该集合已包含相同类型的项目...

2 个答案: