ComboBoxAdv not rendering correctly if nested in Expander-Control

[Patrick Hennig]

In my application I have a ComboBoxAdv with binded SelectedItems and filled via ViewModel. This Box is nested in an Expander. I noticed that the Control isn't shown with values and doesn't open on mouseclick on the first time the view is shown. If I switch to another view and back to the first one the Control is shown with values and opens via mouseclick.

I copied the ComboBoxAdv outside of the Expander. The Control is now shown twice. The Control outside of the Expander is correct directly. The nested one still has the problem.

Any idea?

[Aravindhan P]

Hi Patrick Hennig,

We have validated your query and prepared a sample based on the details you shared. In our testing, the issue could not be reproduced the ComboBoxAdv nested inside the Expander rendered and functioned correctly.

To help us analyze further and provide a precise solution, could you please share the following:

1. The exact code snippet of the control where the issue occurs in your application.
2. A modified sample and video that replicates the problem on your side.

This additional information will allow us to investigate the behavior in your specific scenario and suggest the appropriate fix.

Regards,

Aravindhan Periyasamy

Attachment: ComboBoxExpanderWPF_869320ae.zip

[Patrick Hennig]

After checking the provided code, it turned out to be a race condition that apparently only affected the expander combo box. Even though that doesn't make sense.

Thanks!

[Nithi Sneha Samuel Jeba Kumar]

Hi Patrick,
 

Thank you for your response. From our side, the issue is still not replicable. We have multiple ComboBoxAdv controls nested inside an Expander, and when clicking them the items are displayed correctly.

Could you please share the exact replication procedure you followed to reproduce the issue? A sample from your side would also be very helpful so we can compare against our implementation.

 Additionally, we have sent a video for your reference that shows the behavior we are seeing.

 

Regards,
Nithi Sneha S

Attachment: ComboboxAdv_ddba16a9.zip