Thank you for your interest in our RadRadialMenu control.
The open/close functionality of the RadialMenuButton is built in and unfortunately, cannot be changed. An approach which you could try is to extract and edit the default template of the control. You can take a look at the Editing Control Templates help article which demonstrates how you can extract the control template of the controls. In your case, in the extracted template you can navigate to the RadialMenuButton button and subscribe to its Click event. In the event handler, you can execute your own logic and handle the event afterward.
For your convenience, I have created sample project which demonstrates this approach. Give it a try and let me know if it works for you.
Regards,
Dinko
Progress Telerik
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