Exam 70-483 topic 2 question 51 discussion

Actual exam question from Microsoft's 70-483

Question #: 51
Topic #: 2

An application contains code that measures reaction times. The code runs the timer on a thread separate from the user interface. The application includes the following code. (Line numbers are included for reference only.)

You need to ensure that the application cancels the timer when the user presses the Enter key.
Which code segment should you insert at line 14?

A. tokenSource.Token.Register( () => tokenSource.Cancel() );
B. tokenSource.Cancel();
C. tokenSource.IsCancellationRequested = true;
D. tokenSource.Dispose();

Show Suggested Answer

Suggested Answer: B 🗳️

by supersunny at July 24, 2019, 10:35 a.m.

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supersunny

Highly Voted 5 years, 11 months ago

B. tokenSource.Cancel

upvoted 12 times

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noussa

Most Recent 4 years, 5 months ago

This is why it's B and not C as I thought in the beginning: This property indicates whether cancellation has been requested for this token, either through the token initially being constructed in a canceled state, or through calling Cancel on the token's associated CancellationTokenSource. If this property is true, it only guarantees that cancellation has been requested. It does not guarantee that every registered handler has finished executing, nor that cancellation requests have finished propagating to all registered handlers. Additional synchronization may be required, particularly in situations where related objects are being canceled concurrently.

upvoted 1 times

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Epit2021

4 years, 6 months ago

N.B. The code doesn't actually check what key was pressed, so it'll always stop the timer.

upvoted 1 times

dutohlav

4 years, 5 months ago

There is Readline() - it can only be sent using Enter. It just ignores what the user wrote into the console before hitting Enter (unlike ReadKey())

upvoted 2 times

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