Detect if user copied text from textfield

I want to use the word that user copies from my app textfield.

I found this code:

NotificationCenter.default.addObserver(self, selector: #selector(clipboardChanged), name: UIPasteboard.changedNotification, object: nil)

But 'clipboardChanged' function not calling when copying text from textfield.

I use Swift 4.2

This Code Just Worked Fine For Me:

    override func copy(_ sender: Any?) {
        super.copy()
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        NotificationCenter.default.addObserver(self, selector: #selector(clipboardChanged), name: UIPasteboard.changedNotification, object: nil)
    }

    @objc func clipboardChanged(){
        print("Cut/Copy Performed")
    }

There are many ways of achieving copy Notification

1. UIMenuController

Displays a menu with Copy, Cut, Paste, Select, and Select All commands above or below the selection.

Refer:

https://developer.apple.com/documentation/uikit/uimenucontroller

https://nshipster.com/uimenucontroller/

2. UIResponderStandardEditActions Protocol

Responders implement methods declared in this informal protocol to handle the chosen menu commands (for example, copy: and paste:). Since your UIViewController inherits from UIResponder which indeed conforms to UIResponderStandardEditActions, so it will give you error saying Redundant conformance. So just implement the methods you need directly.

Refer: https://developer.apple.com/documentation/uikit/uiresponderstandardeditactions

3. UIPasteboard changedNotification

class let changedNotification: NSNotification.Name

This happens at the same time the pasteboard’s change count (changeCount property) is incremented. Changes include the addition, removal, and modification of pasteboard items.

Refer: https://developer.apple.com/documentation/uikit/uipasteboard