Non-Blocking Dialog Box Using Queues

When using the One Button Dialog VI, any code downstream of the One Button Dialog VI will not be executed until the user presses the "OK" button. This is considered a "blocking" dialog box. A non-blocking dialog box is a dialog box that does not stop the execution of the rest of the code while waiting on the user to press the "OK" button. There are several ways to create non-blocking dialog boxes.

The most efficient and robust way to create a non-blocking dialog box is to utilize a queued producer/consumer architecture. In the producer loop, a dialog message is enqueued. In the consumer loop, the dialog message is dequeued and sent to the One Button Dialog VI. This enables the code in the producer loop to continue executing while the consumer loop is paused, waiting for the user to press the OK button.

This VI shows how to create a Non-Blocking Dialog Box with
a producer/consumer architecture using queues.

Directions:
1) Run the VI and watch the current time elapse
2) Select Blocking and press Display Dialog Box.
- Notice how the current time stops updating. Click OK.
3) Select Non-Blocking and press Display Dialog Box.
- Notice how the current time continues to elapse.
4) Press Stop to stop the VI.

Related Links:

KnowledgeBase DIRECT-3S8RDE: What Is a Queue?

Developer Zone Tutorial: Application Design Patterns: Producer/Consumer

Requirements

Filename: nonblockingdialogbox.vi

Software Requirements

Application Software: LabVIEW Full Development System 7.0
Language(s): LabVIEW

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