No invalidation is needed.
Do you think the author of the property
is an idiot? Of course the client area of a radio button is invalidated when a new value (different from the previous one) is assigned to the property; this is done via the property setter
I don't know the exact reason of you observation that "assigning the new string to the ->Text property has no impact", but I'm certain it must be your mistake
. There can be different reasons: the new value is not really new, the assignment operator is actually not called, UI is hanging by some reason, etc. You can easily run your code under Debugger to see what's going on. Actually, you should do it before asking a question like that, very likely — instead of asking the question
Do you homework in order to succeed.