(First off, “affect” is a verb; “effect” is a noun. I see people get this one wrong frequently. Pardon my inner grammar nazi.)
The “fact” that a full moon triggers a person’s transformation into a werewolf is a neat bit of canon that was largely made up by Hollywood; the influence of screenwriter Curt Siodmak, who wrote the script for Universal’s THE WOLFMAN, cannot be overstated. I use the full moon motif myself in my new novel THE CONFESSIONS OF SAINT CHRISTOPHER: WEREWOLF. (Shameless plug time! The book is only $2.99! And thanks, Curt!) If we take the full moon thing and run with it, presuming that (a.) werewolves exist and (b.) a full moon will trigger a lycanthropic transformation into such, how then would a full solar eclipse affect a werewolf? It does involve the full moon. Considering that a full moon is really just the moon reflecting sunlight, anyway, would an eclipse cause a werewolf to transform? Would it trigger some special kind of transformation, the way red or white Kryptonite used to affect Superman in the comics and on the SUPER FRIENDS cartoon, like making him grow an extra leg or something? Or is the moon’s umbra as potent as its “shine”? More potent? The possibilities are endless.
As I write this, the eclipse is only some four hours away. If we see an upsurge in sightings of five-legged werewolves during the period of occlusion, we’ll have our answer, I reckon.