When the DeleteEvent is called by a Gtk# window, how can I prevent the window from closing?

Question

When the window closes, the user is asked to save the file that they edited. They should also have an option to cancel quitting the application.

In WPF I can set the CancelEventArgs.Cancel property to true to do this. Is there an equivalent/workaround in Gtk#?

Answer 1

Found this python example (link) from a quick google search:

# When the window is requested to be closed, we need to check if they have 
# unsaved work. We use this callback to prompt the user to save their work 
# before they exit the application. From the "delete-event" signal, we can 
# choose to effectively cancel the close based on the value we return.
def on_window_delete_event(self, widget, event, data=None):

    if self.check_for_save(): self.on_save_menu_item_activate(None, None)
    return False # Propogate event

Hopefully this helps.

Answer 2

You need to set the DeleteEventArgs.RetVal to true, not false. From the relevant Mono documentation:

To keep a Gtk.Window from closing, set Gtk.DeleteEventHandler's Gtk.DeleteEventArgs.RetVal to true.