Access to token when the Task action is defined in another scope

[TPucke]

I'm using the overload Task.Run(Action, CancellationToken). The example code shows how to handle the cancellation, but the token variable inside the anonymous action appears to be available because it is declared in the outer scope. How is a cancellation token accessed within the action body when the action is defined in another scope, such as in another class. I have made this work by passing the token both as second argument to Task.Run and as an argument to my action method, but surely it is not intended that this token should have to be passed twice (redundantly). Since the token is passed to Task.Run it must be available inside the action by some local reference.

Enhancing the example code with this more general usage would be helpful.

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• ID: 53ffa5ba-8804-d68e-50e8-a28c25506dc3
• Version Independent ID: 6d39fed4-8dc0-1907-8d92-9e30c0907369
• Content: Task.Run Method (System.Threading.Tasks)
• Content Source: xml/System.Threading.Tasks/Task.xml
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• GitHub Login: @dotnet-bot
• Microsoft Alias: dotnetcontent

[TPucke]

Just registering my continued interest in this topic. I have a piece of sloppy code that I would like to make clean with guidance from MS.

[svick]

No, there is no provided way to access the CancellationToken from inside the lambda. Passing it twice is the common usage, if you can't directly access it from the outer scope, like the example does.

[TPucke]

Sad to hear that, but OK thanks for letting me know. As for the subject documentation, it could be helpful then to clarify this by providing a minimal example (using a CancellationToken) where Task.Run is used to run code that is not an in-line lambda (e.g. a method of arbitrary class), so that the convenient scope of the current example does not obscure this point.