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Eventcallback doesn´t fire .NET




I´m using a .NET control ( ) which can be downloaded on This is a control for generating a Gantt Chart. This control proviedes me some callback events I want to handle with LabVIEW. I attached a small example to demonstrate the behavior. Some of the callback VIs are executed as expected an some VIs doesn´t fire so I didn´t get the event in LabVIEW.

For example the BarResize Event doesn´t work but the DblClick works fine. I already talked to the developer of the control but we couldn´t solve the problem. What could be a reason in a .NET dll for LabVIEW to have problems?


LV-Version 2010SP1




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Sorry that it took so long, I have been trying to get this to work for quite some time now. 


So, ultimately, I tried to recreate your example in C# to test if the product you use is programmed correctly. 

You can find my results in the attachment.


It is basically the same things you do in LabVIEW, recreated in C#. Here, both events fire correctly as they should.

I honestly do not know why it does not work in LabVIEW, and I had a colleague with a lot of expertise look at your code,

there seems to be no error in it. 


So, what I can offer you is to contact someone closer to R&D on this issue.




NI AE Germany

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thank you for your answer. The developer of the exontrol .net control installed a Labview environment an did some tests. He finds out that changing the event data from the BarResize event (object sender, int Item, object Key) to (object sender, int Item, string Key) the event fired as expected. He builds a new testversion of the .dll with a BarResize2 event which has the different data typ.

Maybe this is an important hint for finding the reason. By the way, I tried different Labview Versions too.

I attached the new test .dll for you to have a look on it.




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 i think you finally realized the function of attatched the .dll,but i can not open to do that.

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