objective-C method how to call between two viewcontroller

I would like to call in viewcontroller A method in viewcontroller B, how to achieve?
Reply:
viewController * b1 = [[viewController alloc] init];
[Self.navigationController pushViewController: b1 animated: YES];
[B1 release];
Reply:
oc is the object-oriented language, ah, use [object method];
General use delegate, do not recommend notice.

Reply:
Set up in the B final in a public function, and then the A in the argument to pass into it ~ ~