[ Version ( since = "2.28" ) ]
public abstract unowned VariantType? get_parameter_type ()
Queries the type of the parameter that must be given when activating this.
When activating the action using activate, the Variant given to that function must be of the type returned by this function.
In the case that this function returns null, you must not give any Variant, but null instead.
| this |
a Action |
|
the parameter type |