解包可选的 IBOutlet 时出现错误（线程 1：致命错误：解包可选值时意外发现 nil）

Question

I know why this problem is happening but I don't know how to fix it. I used an override func to add to the method becomeFirstResponder (which does exactly what it says) from the class ViewController to my IBOutlet autoKeyboard. How do I get this to not be of nil value? Do I give my IBOutlet a value instead of using the “!” ?

What this does: Makes the keyboard pop up automatically instead of tapping on the text field (kind of like in spotlight search on iOS)

Let me know if I need to send more information!

override func becomeFirstResponder() -> Bool {

autoKeyboard.becomeFirstResponder()
return true

}

The error I'm given is:

Thread 1: Fatal error: Unexpectedly found nil while unwrapping an Optional value

Answer 1

The reason you are getting a nil value is because your nib has not been initialized yet, thus your textfield is nil. I think you are calling your becomeFirstResponder on your textfield too early in the view controller life cycle.

Answer 2

I made the IBObject autoKeyboard an optional and thus changed the line of code to the following:

    override func viewDidAppear(_ animated: Bool) {
    autoKeyboard?.becomeFirstResponder()
}

It now works!