Did Frodo and Gandalf actually meet before Bilbo and Frodo's party?

[Annunfuiniel]

They knew him by sight, though he only appeared in Hobbiton occasionally and never stopped long;

The hobbit children knew Gandalf by sight so I deem he had been there more than once even during their lifetime. And Frodo had lived at Bag End for about 12 years by the time of The Party so he would definitely have met Gandalf at least couple of times. Maybe their acquaintance deepened into true friendship only after Bilbo's departure and Frodo's coming of age. Knowing Frodo had his rascal period while in his tweens (and earlier; referring to farmer Maggot and his mushrooms ) I can well imagine what might have happened if Gandalf let his fireworks unguarded:

*KA-BOOOOOM!!*

"Fool of a Baggins!"

Sorry....