OperationContext.Current是采用异步时，首先计谋后空/等待在WCF服务

问题描述

我使用异步/等待在.NET 4.5模式来实现一些服务方法WCF。例如服务：

I am using async/await pattern in .NET 4.5 to implement some service methods in WCF.Example service:

合同：

[ServiceContract(Namespace = "http://async.test/")]
public interface IAsyncTest
{
    Task DoSomethingAsync();
}

执行：

MyAsyncService : IAsyncTest
{
    public async Task DoSomethingAsync()
    {
        var context = OperationContext.Current; // context is present

        await Task.Delay(10);

        context = OperationContext.Current; // context is null
    }
}

我遇到的问题是，经过第一个等待 OperationContext.Current 返回空，我无法访问 OperationContext.Current.IncomingMessageHeaders 。

The problem I am having is that after first await OperationContext.Current returns null and I can't access OperationContext.Current.IncomingMessageHeaders.

在这个简单的例子，这不是一个问题，因为我可以捕捉在计谋的范围内。但在现实世界的情况下 OperationContext.Current 从调用堆栈深处被访问，我真的不想改变很多code只是通过范围内进一步。

In this simple example this is not a problem since I can capture the context before the await. But in the real world case OperationContext.Current is being accessed from deep inside the call stack and I really don't want to change lots of code just to pass the context further.

有没有办法在来获取操作方面等待点，而无需手动传递下来的堆？

Is there a way to get operation context after await point without passing it down the stack manually?

推荐答案

我觉得你最好的选择是真正抓住它，然后手动将它传递。您可能会发现这提高了你的code中的可测性。

I think your best option is to actually capture it and pass it manually. You may find this improves the testability of your code.

这是说，有一对夫妇的其他选项：

That said, there are a couple of other options:

1. 将其添加到 LogicalCallContext 。
2. 在安装自己的的SynchronizationContext 这将设置 OperationContext.Current 时，它做了发布;这是怎么了ASP.NET preserves其 HttpContext.Current 。
3. 在安装自己的的TaskScheduler 这台 OperationContext.Current 。

1. Add it to the LogicalCallContext.
2. Install your own SynchronizationContext which will set OperationContext.Current when it does a Post; this is how ASP.NET preserves its HttpContext.Current.
3. Install your own TaskScheduler which sets OperationContext.Current.

您可能还需要在Microsoft Connect上提出这个问题。

You may also want to raise this issue on Microsoft Connect.

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