Service Fabric -- CreateServiceInstanceListeners -- 多个侦听器 -- "yield return" 或 "return new[]"答案

【问题标题】：Service Fabric -- CreateServiceInstanceListeners -- Multiple Listeners -- "yield return" or "return new[]"Service Fabric -- CreateServiceInstanceListeners -- 多个侦听器 -- "yield return" 或 "return new[]"
【发布时间】：2019-01-18 17:24:19
【问题描述】：

如果您的 Service Fabric 服务有多个侦听器，我注意到您可以使用 2 种不同的模式创建 CreateServiceInstanceListeners。（.Net 框架/有状态/无状态）

第一种方法是产生返回值，而第二种方法是返回一个数组。

protected override IEnumerable<ServiceInstanceListener> CreateServiceInstanceListeners()
{
    yield return new ServiceInstanceListener(serviceContext => new OwinCommunicationListener(Startup.ConfigureApp, serviceContext, ServiceEventSource.Current, "ServiceEndpoint")),
    yield return new ServiceInstanceListener(wcfContext => new WcfCommunicationListener<IWebApi>(wcfServiceObject: this, serviceContext: wcfContext,endpointResourceName: "WcfEndpoint",listenerBinding: WcfUtility.CreateTcpListenerBinding()),"WcfEndpoint")
}

对

protected override IEnumerable<ServiceInstanceListener> CreateServiceInstanceListeners()
{
    return new[]
    {
        new ServiceInstanceListener(serviceContext => new OwinCommunicationListener(Startup.ConfigureApp, serviceContext, ServiceEventSource.Current, "ServiceEndpoint")),
        new ServiceInstanceListener(wcfContext => new WcfCommunicationListener<IWebApi>(wcfServiceObject: this, serviceContext: wcfContext,endpointResourceName: "WcfEndpoint",listenerBinding: WcfUtility.CreateTcpListenerBinding()),"WcfEndpoint")
    };
}

使用一个比另一个有什么优势吗？

【问题讨论】：

标签： azure-service-fabric

【解决方案1】：

没有太大区别。每个服务实例对返回的枚举进行一次迭代。

这是从GitHub 上截取的代码。

if (this.instanceListeners == null)
{
    this.instanceListeners = this.userServiceInstance.CreateServiceInstanceListeners();
}

var endpointsCollection = new ServiceEndpointCollection();
var listenerOpenedCount = 0;

foreach (var entry in this.instanceListeners)
{
    var communicationListener = entry.CreateCommunicationListener(this.serviceContext);
    this.AddCommunicationListener(communicationListener);
    var endpointAddress = await communicationListener.OpenAsync(cancellationToken);
    endpointsCollection.AddEndpoint(entry.Name, endpointAddress);
    listenerOpenedCount++;

    var traceMsg = entry.Name.Equals(ServiceInstanceListener.DefaultName)
        ? "Opened communication listener with default name."
        : $"Opened communication listener with name {entry.Name}.";

    ServiceTrace.Source.WriteInfoWithId(TraceType, this.traceId, traceMsg);
}

【讨论】：