Hi,
The beforeunload event is fired when the document and its resources are about to be unloaded.
By default refreshing the RadGrid causes a complete PostBack of the page and therefore the page is unloaded and loaded again, respectively the beforeunload event is fired.
To avoid reloading the whole page, and firing the beforeunload event, when a PostBack is forced by the RadGrid, you can enable AJAX for the RadGrid using one of the following approaches:
Check out the Understanding AJAX Controls article to get a better overview of Ajaxifying Controls.
I hope this will prove helpful!
Kind regards,
Doncho
Progress Telerik
Progress is here for your business, like always.
Read more about the measures we are taking to ensure business continuity and help fight the COVID-19 pandemic.
Our thoughts here at Progress are with those affected by the outbreak.