Those charges included aggravated robbery with a firearm, wounding with intent to cause grievous bodily harm, unlawful possession of a firearm, and discharging a firearm to intimidate.
The gun was also recovered on Monday afternoon, Harris said.
Police would oppose bail when the man appeared in court.
“There’s no place for callous violence in which puts law-abiding members of the public in harm’s way. You will be held to account,” Harris said.
Harris acknowledged Whangārei residents who contacted police with information throughout the weekend.
Earlier, Kensington Tavern owner Craig Woods told RNZ a man wielding a gun burst into the premises via the smoker’s area, went behind the bar, and demanded staff give him money from the till.
He said two staff members and three customers were still in the pub at the time.
“The staff did the correct thing by giving them the till, and it all happened pretty quickly. But one of the patrons intervened. The offender sort of broke free, and so the patron backed off.”
Woods said the patron fell after his tussle with the robber and hit his head, which required stitches.
St John Ambulance said one person was taken to hospital with moderate injuries.