GtkBuilder | About tag:signal How to set the object property

Why is only the GObject type allowed to be passed?

Why not try looking in scope?

Because the XML does not know anything about random memory in your C application.

You can only pass an object as an argument because it can reference the buildable id that GtkBuilder can then retrieve and use as the argument for g_signal_connect().

I use gtk_builder_list_item_factory_new_from_resource Build GtklistItem, each item has a button, and the release event needs to accept a parameter.

The second parameter of my callback function is GtkListItem, which occupies the userdata position.
And GtkListItem I found out how to customize the way of data.

I know it is possible to add custom data to GObject, can it be implemented in XML?

So how do I get my data in the callback function?