Batman Dark Knight Figures In Dark Knight, How Did Batman Complete The Joker?

In Dark Knight, How did Batman complete the Joker? - batman dark knight figures

I see in the movie The Dark Knight, dozens of times, but I still can not understand yet, like Batman Joker really complete? As the Joker in Batman the police station, he (Batman), fill it (Joker)

I know the old movie, know and understand how the Joker Batman is completed, but as the Joker in The Dark Knight is different from how the Joker for Batman complete?

Just A Wondering