How to write init methods of a UIViewController in Swift

Question

I am unable to add init method to the following UIViewController class. I need to write some code in the init method. Do i have to write init(coder) method? Even when I add

Answer 1

You need to override the init(nibName:bundle:) initializer, and provide the init(coder:) required initializer, and initialize tap in both of them:

class ViewController: UIViewController {

    var tap: UITapGestureRecognizer?

    override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: Bundle?)   {
        print("init nibName style")
        super.init(nibName: nibNameOrNil, bundle: nibBundleOrNil)
        tap = UITapGestureRecognizer(target: self, action: Selector("handleTap:"))
    }

    // note slightly new syntax for 2017
    required init?(coder aDecoder: NSCoder) {
        print("init coder style")
        super.init(coder: aDecoder)
        tap = UITapGestureRecognizer(target: self, action: Selector("handleTap:"))
    }
...
...
}

Also, be sure when calling the superclass initializer that you don't just pass nil for the nibName and bundle. You should pass up whatever was passed in.

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Note that the "convenience init" method mentioned in some answers is only relevant if you are actually "by hand" yourself initializing a view controller. (There are very few situations where you would do that.) If you want to "do something during normal initialization" - so for example create a gesture recognizer or just initialize some variables - the only possible solution is exactly the one given in this answer.