List of active audio users not received in callback


Hello. I am using windows-sdk to join a meeting and I am using the AudioCtrlEvent->onUserActiveAudioChange method to detect when the active speaking user is changed. So I am getting the callback on this method, but the IList of activeAudioUsers that is received has a count of 0 i.e. list->GetCount() returns 0. However, when trying with the demo app present on github, the callback receives the non empty list with user ids of active users. Am I missing some step ? I couldn’t find any documentation on how to use the AudioCtrlEvent.

P.S. I am receiving the callback but with empty list of active users.


anyone aware of the problem ??


sorry for miss the thread. if the activeaudiolist->getcount() returns 0, means now no active speaker in the meeting, you can clear the latest active speaker status.




@dats. Yes that is the desired behavior. But the API is returning zero even when there is an active speaker. When someone in the meeting starts speaking, the callback is received on the method but the list of active users has count 0 only.

And just for reminder, this happens in the zoom client that I am implementing, on the sample app , the callback is working fine.


maybe some bugs in our c# wrap, let me check. 




I am using the C++ sdk


no special step about audioctrlevent, if ok for u, you can share your code for me about this callback.




You can check the code here.

I have shared the code of a Controller that I have written for calling the zoom APIs. 

In my main method I call following methods in the order given

zoomcontroller.init(sdkKey, sdkSecret)





please help to double check the following items

  1. did you call our api in sub-thread? if yes, please switch to main thread to call our api

2.did your app has message loop in main thread? because our sdk depends on windows message loop.




The API is being called from Main thread only.

And I also have a message loop in place.

You can refer to waitForCallback() method, it implements the message loop.

If there had been no message loop I couldn’t have received the callback. But problem is not that. I am receiving the callback, but, with empty list of active users.


if ok for u, could you send your app to us, binary or installer is enough, no need source code. I need to debug on this.




ok. i can share the binary with you. give me 5 mins


You can download the zip with binary and dlls from here. 

Please refer to ReadMe for details about using binary



already follow the readme to config key and secret, but also got “Inside Main function
SDK_KEY or SDK_SECRET not set in config file”




The format should be 

SDK_KEY=<Value of SDK_KEY>



Also, the config file should be located in the folder from where exe is being called.

For ex. if you are calling the exe from some other folder, config file should be in that folder only.



please switch your app from Console Application to Win32 windows app, and try again. now we don’t support integration with Console Application.




Ohh. That might be the reason it was working in sample app. Thank You very much for your help.
i have been looking for answer for quite a few time.


you are welcome. sorry to be so late reply to you.




For any future reference, are all these things documented any where ?

Like console application is not supported, APIs need to be called from Main thread, a Message Loop is required to received callbacks ?


Good suggestion, Thanks, we are working on to improve our document.