UIButton remove all target-actions
Call removeTarget:action:forControlEvents:, pass nil for the target, NULL for action, and use a control mask that sets all bits (UIControlEventAllEvents).
Objective-C
[someControl removeTarget:nil action:NULL forControlEvents:UIControlEventAllEvents];
Swift 2
button.removeTarget(nil, action: nil, forControlEvents: .AllEvents)
Swift 3 or higher
button.removeTarget(nil, action: nil, for: .allEvents)