# Register a callback on a GenICam node change

**URL:** <https://forum.commonvisionblox.com/t/register-a-callback-on-a-genicam-node-change/878>\
**Category:** .Net API\
**Created:** [September 16, 2019, 8:39am UTC](https://forum.commonvisionblox.com/t/register-a-callback-on-a-genicam-node-change/878 "2019-09-16T08:39:53Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![MarSch](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.commonvisionblox.com/marsch/32/23_2.png) [@MarSch](https://forum.commonvisionblox.com/u/MarSch)\
**Post date:** [September 16, 2019, 8:39am UTC](https://forum.commonvisionblox.com/t/register-a-callback-on-a-genicam-node-change/878/1 "2019-09-16T08:39:53Z")

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With the C-style API for C#, registering a callback on a node change was relatively straightforward with NRegisterUpdate().

It would be interesting to see how this is thought to be implemented with the .Net API.

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**Author:** ![Moli](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.commonvisionblox.com/moli/32/553_2.png) [@Moli](https://forum.commonvisionblox.com/u/Moli)\
**Post date:** [September 16, 2019, 10:46am UTC](https://forum.commonvisionblox.com/t/register-a-callback-on-a-genicam-node-change/878/2 "2019-09-16T10:46:39Z")

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Hi,

I once tried the same thing and were able to do it in C++ (which should be based on the same principles).  
Please check the following thread for code samples:  
[https://forum.commonvisionblox.com/t/gige-vision-events-c/510](https://forum.commonvisionblox.com/t/gige-vision-events-c/510)

Best regards,  
MoLi

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**Author:** ![TStadler](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.commonvisionblox.com/tstadler/32/308_2.png) [@TStadler](https://forum.commonvisionblox.com/u/TStadler)\
**Post date:** [September 16, 2019, 12:33pm UTC](https://forum.commonvisionblox.com/t/register-a-callback-on-a-genicam-node-change/878/3 "2019-09-16T12:33:00Z")

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Hi @MarSch,  
this is really easy in [Cvb.net](http://Cvb.net).  
As soon as you have an object of your node, you can register the .Updated event like this:

> ```
> FloatNode fps = (FloatNode)nodeMap["Std::AcquisitionFrameRate"];
> fps.Updated += FpsNode_Updated;
> 
> ```

Be aware though, that the Updated event is triggered when ANY property of the node updates. This could be for examle the IsWritable property, or even the Min and Max, if it’s a ValueNode.

Regards,  
Tim

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<div class="post-metadata">

**Author:** ![MarSch](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.commonvisionblox.com/marsch/32/23_2.png) [@MarSch](https://forum.commonvisionblox.com/u/MarSch)\
**Post date:** [September 17, 2019, 8:26am UTC](https://forum.commonvisionblox.com/t/register-a-callback-on-a-genicam-node-change/878/4 "2019-09-17T08:26:17Z")

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Oh, probably too simple - with just assigning a handler function. Works nicely, thank you.

Best,  
Markus