Gets the #GDBusConnection being used by the application, or null.
If #GApplication is using its D-Bus backend then this function will
return the #GDBusConnection being used for uniqueness and
communication with the desktop environment and other instances of the
application.
If #GApplication is not using D-Bus then this function will return
null. This includes the situation where the D-Bus backend would
normally be in use but we were unable to connect to the bus.
Gets the #GDBusConnection being used by the application, or null.
If #GApplication is using its D-Bus backend then this function will return the #GDBusConnection being used for uniqueness and communication with the desktop environment and other instances of the application.
If #GApplication is not using D-Bus then this function will return null. This includes the situation where the D-Bus backend would normally be in use but we were unable to connect to the bus.
This function must not be called before the application has been registered. See gio.application.Application.getIsRegistered.