.net event callback VIs - Why do they never leave running state?

[JimB.]

You don't need a constructor, just an invoke node.

[wiebe@CARYA]

Does this unlock callback VI's for LabVIEW events as well? Don't see why it would...

The Register Callback Event node can be used to register events for control, pane, VI, etc references. However, when the callback VI's are in a class, they will never unlock, and since one VI in the class is locked, the entire class stays locked. Closing the project is the only way out.

[UFOslava]

Why would this be a thing?

This messes up my workflow…

[wiebe@CARYA]

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@UFOslava wrote:

Why would this be a thing?

This messes up my workflow…

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Why would what a thing?

What messes up your workflow?

[UFOslava]

Restarting LabView after each run of my code.

[wiebe@CARYA]

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@UFOslava wrote:

Restarting LabView after each run of my code.

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I think closing the project is enough, but yes, it's a pain.

[pawhan11]

It seems that in some scenarios this problem exists for LV controlls callback Events. VI can not be unloaded and upon exit labview crashes...

<DEBUG_OUTPUT>
2019-01-14 15:21:39.408
DWarn 0x30EA5E5C: no master part
e:\builds\penguin\labview\branches\2018patch\dev\source\panel\fpinval.cpp(235) : DWarn 0x30EA5E5C: no master part
minidump id: 237f3a14-5287-4877-ae3b-dca69607e6e2
$Id: //labview/branches/2018patch/dev/source/panel/fpinval.cpp#1 $

Is there known CAR reported for this or workaround?

[GeraldM]

Hello pawhan11,

The CAR number for the original post is 493624. Have you tried implementing the workaround listed? It should still work.

Also, I would suggest that you make a new forum post for your particular issue because it seems to be different than the original post and this thread is an older one. Moving to a new thread will potentially get more attention by active users on the forums.

[wiebe@CARYA]

The only workaround, Collect, only (potentially) works for .NET callbacks. AFAIK, there is no workaround for hanging callback events on native LabVIEW objects.

[Mac671]

Thanks for pointing this KB article out this has helped me. I'm using LV2019 I found no other way to fix this other than calling GC.Collect() after calling the Unregister for Events. If anyone knows of a more proper fix for this I'd appreciate it.