Does anyone know how to evolve Riolu in Pokemon Black 2?

I have a Riolu, level 17, and I want to evolve it. I know that I need to level it up with high happiness during the daytime; I tried that and it didn't work. I know how to check the happiness and it seems to be pretty high (Bianca says "You two sure get along great! It looks like you are having fun being together! You seem bright and cheerful!"), and I leveled it up at 11:15 AM with that happiness, but it didn't evolve. Am I doing something wrong? And if I need to increase the happiness, how can I do so? I have looked this question up on Google but it just told me to ride my bicycle and feed the Riolu vitamins, but I don't have a bicycle and vitamins aren't available in the store thing at the Pokemon Centre. If my stage in the game is relevant, I have my first Gym Badge and I'm currently training my Pokemon for the second gym battle. So, does anyone know how I can evolve my Riolu?

You can also walk around with riolu thta increases happiness too. Its very slow but i think its the only option now.

Keep battling with him until he reaches the required level at daytime. Battling and leveling up will make him become more happy, thus evolving into Lucario. There's no telling what level it will evolve, but keep fighting your way into evolution.

Thanks both of you, I got it to evolve the friendship level never increased but it somehow evolved at level 18, maybe something to do with me playing it in the evening.

It doesn't have anything to do with playing in the evening but congrats with your new Lucario