在另一个 WCF 服务中的阻塞调用中轮询 WCF 服务方法

Question

更新：

问题已解决。这两段代码实际上都有效。一个潜在的问题导致失败。

我不是线程专家，但这是我的场景。

我有两个 WCF 服务（ServiceA 和 ServiceB）

ServiceA 必须

每秒或配置的时间间隔轮询 ServiceB，
对于某种状态，
阻塞直到 ServiceB 返回所需状态
ServiceA 方法然后继续其下一个操作

专注于 Service A 的实现以实现要求，并假设我正在使用为 Service B 生成的服务引用，干净地处理和关闭，定义了接口：

public class ServiceA : IServiceA
{
   public ResultObject ServiceAMethod()
   {
       var serviceBClient = new ServiceBReference.ServiceBClient();
       //do sometthing
       //call ServiceB every 1second until the status changes or a WCF timeout ends the process
       return new ResultObject{/*set whatever properties need to be set*/}
    }
}

我试过没有屏蔽的：

尝试 1

public class ServiceA : IServiceA
{
   public ResultObject ServiceAMethod()
   {
        var serviceBClient = new ServiceBReference.ServiceBClient();
        //do sometthing
        //call ServiceB every 1second until the status changes or a WCF timeout ends the process

        var cancellationTokenSource = new CancellationTokenSource();
        var token = cancellationTokenSource.Token;

        SomeStatusEnum status;
        int pollingInterval = 1000;
        var listener = Task.Factory.StartNew(() =>
        {
            status = serviceBClient.GetStatus();
            while (status != SomeStatusEnum.Approved)
            {
                Thread.Sleep(pollingInterval);
                if (token.IsCancellationRequested)
                    break;

                status = serviceBClient.GetStatus();
            }
        }, token, TaskCreationOptions.LongRunning, TaskScheduler.Default);
       return new ResultObject{/*set whatever properties need to be set determined by status*/}
    }
}
}

尝试 2

public class ServiceA : IServiceA
{
   public ResultObject ServiceAMethod()
   {
        var serviceBClient = new ServiceBReference.ServiceBClient();
        //do sometthing
        //call ServiceB every 1second until the status changes or a WCF timeout ends the process

        SomeStatusEnum status;
        int pollingInterval = 1000;

        status = serviceBClient.GetStatus();
        while (status == SomeStatusEnum.Approved)
        {
            status = serviceBClient.GetStatus();;
            if (status != SomeStatusEnum.Approved)
            {
                break;
            }
            Thread.Sleep(pollingInterval);
        }
       return new ResultObject{/*set whatever properties need to be set determined by status*/}
    }
}

在这两种情况下，状态都不会设置为预期值。我做错了什么？是否存在可能导致此问题的与 WCF 应用程序关联的行为？

我的来源:

WCF Thread Sleep
C# error System.NullReferenceException
Calling a method every x minutes
When to use Task.Delay, when to use Thread.Sleep?

Answer 1

这两段代码确实有效。

可以删除问题，但选择保留它以供参考，因为它还包括可能对下一个人有帮助的参考。

在另一个 WCF 服务中的阻塞调用中轮询 WCF 服务方法

Polling a WCF service method in a blocking call within a another WCF service

c#

wcf

task

blocking