Hello again, @lu7jm!
This one is a no-go right now, for the events related to grouping are not currently wired up to the grid panel (or its view) list of supported listeners (or direct events).
So although we have implemented support for specifying the features
block in the latest iteration of to-be-released Ext.NET 7 preview4, without the ability to handle the feature's events it is pretty much unusable.
If you want to try how far you can go with that, to the grid panel you'd need to add the following block:
To the grid's store, you have to tell which field should be grouped:
<ext-store groupField="Light" />
This should work in the latest Ext.NET 7.0.0-preview4 build -- not in publicly released 7.0.0-preview3; and it also should not work in any partial 7.0.0-preview4 package built before today, Jun 19th, 2020. If you want to give the above a try, you may request a copy of the latest build of Ext.NET 7 at email@example.com
I will not go as far as provide a running sample over the sample you pointed as it relies in grouping related events, so it is not currently possible to reproduce the example in Ext.NET 7. But grouping is now possible to be enabled; just the events are missing.
We have logged this missing bit under issue #1785 on GitHub
and will post an update here as soon as the issue gets fixed.
Hope this helps!