/*do something in ParentClass*/
/*try interrupting [child method]*/
/*do something in ChildClass*/
No, you can't control a method up the call chain like this. Nor should a class have this sort of knowledge about its subclasses.
You'll have to find some way for
ClassB to check the condition itself, whether via the return value from
-[ClassA method], or by calling another method first, or checking it directly.