SAN DIEGO — Comic-Con isn’t just a day affair. After the convention center closes for the night, the streets of downtown San Diego come alive with parties galore — dozens of events over the four-day fan festival.

“The Con is for the fans,” comic artist Eric J said as he navigated between parties. “For the professionals and exhibitors, it’s also for networking and making contacts, and that happens at the parties.

“Even though everyone’s having a great time, more business gets done after hours. And it’s not just business. There are friendships made at the convention and at the parties that last a lifetime.”

The festivities began on the eve of Comic-Con with Wednesday’s gathering for “The Twilight Saga: Breaking Dawn — Part 2,” which drew crowds to the Hard Rock Hotel’s rooftop bar. The next night, it hosted a party for “The Expendables 2,” where Arnold Schwarzenegger made an appearance, and Microsoft’s Xbox 360 gathering, where guests previewed games like “Dance Central 3,” “Deadlight” and “Halo 4.”

Saturday’s soirees included Entertainment Weekly’s annual poolside party, and a Playboy and “True Blood” event that promises to recreate the restaurants and landmarks from the HBO show.