Easy way to dismiss keyboard?

You can send a nil targeted action to the application, it'll resign first responder at any time without having to worry about which view currently has first responder status.

Objective-C:

[[UIApplication sharedApplication] sendAction:@selector(resignFirstResponder) to:nil from:nil forEvent:nil];

Swift 3.0:

UIApplication.shared.sendAction(#selector(resignFirstResponder), to: nil, from: nil, for: nil)

Nil targeted actions are common on Mac OS X for menu commands, and here's a use for them on iOS.

You can force the currently-editing view to resign its first responder status with [view endEditing:YES]. This hides the keyboard.

Unlike -[UIResponder resignFirstResponder], -[UIView endEditing:] will search through subviews to find the current first responder. So you can send it to your top-level view (e.g. self.view in a UIViewController) and it will do the right thing.

(This answer previously included a couple of other solutions, which also worked but were more complicated than is necessary. I've removed them to avoid confusion.)

Try:

[self.view endEditing:YES];