_UITextLayoutCanvasView

SecureLabel.swift

import UIKit

  lazy var hiddenView: UIView = {
    let hiddenView: UIView

    // iOS 14.1 -> _UITextFieldCanvasView
    // iOS 15.0 -> _UITextLayoutCanvasView

    if let klass = NSClassFromString("_UITextFieldCanvasView") as? UIView.Type {
      hiddenView = klass.init()
      hiddenView.layer.perform(Selector(("setDisableUpdateMask:")), with: 0x12)
    } else {
      let textField = UITextField()
      textField.isSecureTextEntry = true

      hiddenView = textField.layer.sublayers?.first?.delegate as! UIView
      hiddenView.subviews.forEach { $0.removeFromSuperview() }
    }

    addSubview(hiddenView)
    hiddenView.translatesAutoresizingMaskIntoConstraints = false
    NSLayoutConstraint.activate([
      hiddenView.leftAnchor.constraint(equalTo: leftAnchor),
      hiddenView.rightAnchor.constraint(equalTo: rightAnchor),
      hiddenView.topAnchor.constraint(equalTo: topAnchor),
      hiddenView.bottomAnchor.constraint(equalTo: bottomAnchor)
    ])
    return hiddenView
  }()

  lazy var hiddenLabel: UILabel = {
    let sublabel = UILabel()

    hiddenView.addSubview(sublabel)
    sublabel.translatesAutoresizingMaskIntoConstraints = false
    NSLayoutConstraint.activate([
      sublabel.leftAnchor.constraint(equalTo: hiddenView.leftAnchor),
      sublabel.rightAnchor.constraint(equalTo: hiddenView.rightAnchor),
      sublabel.topAnchor.constraint(equalTo: hiddenView.topAnchor),
      sublabel.bottomAnchor.constraint(equalTo: hiddenView.bottomAnchor)
    ])

    return sublabel
  }()

}

Hi @alidinc,

please try this (please note I have not tested this on iOS 16).

import UIKit
extension UIView {
    func preventScreenshot() {
        guard superview != nil else {
            for subview in subviews {
                subview.preventScreenshot()
            }
            return
        }

        let guardTextField = UITextField()
        guardTextField.backgroundColor = .red
        guardTextField.translatesAutoresizingMaskIntoConstraints = false
        guardTextField.tag = Int.max
        guardTextField.isSecureTextEntry = true

        addSubview(guardTextField)
        guardTextField.isUserInteractionEnabled = false
        sendSubviewToBack(guardTextField)

        layer.superlayer?.addSublayer(guardTextField.layer)
        guardTextField.layer.sublayers?.first?.addSublayer(layer)

        guardTextField.centerYAnchor.constraint(
            equalTo: self.centerYAnchor
        ).isActive = true

        guardTextField.centerXAnchor.constraint(
            equalTo: self.centerXAnchor
        ).isActive = true
    }
}

this works like a charm, 🎉 thanks @0xWDG 🙌

😃

Just noticed, this doesn't work when it's applied to any views on a viewController :/

Just noticed, this doesn't work when it's applied to any views on a viewController :/

Is the view used in SwiftUI? i was not able to get it to work in any SwiftUI views.

For (classic) viewcontrollers, it should work on elements (maybe on the whole view, but never tested that).

What i did was:

class VC: UIViewController {
    @IBOutlet var label1: UILabel!

    override func viewDidLoad() {
        super.viewDidLoad()
    }

    @IBAction func hide(_ sender: Any) {
        self.label1.preventScreenshot()
    }
}

I tried it on a view controller's view in UIKit or any other view covering the entire space as that's what I'm trying to block screenshots for. it only works on a single element like the label you mentioned but not for the entire view.

I want to prevent taking screenshots from the view-controller. Could you give me some advice or guidance?
Because when I tried to add it to view-controller by command self.view.makeSecure(), my app was crashed.

I want to prevent taking screenshots from the view-controller. Could you give me some advice or guidance?
Because when I tried to add it to view-controller by command self.view.makeSecure(), my app was crashed.

Hi @nthnhung23,

It does not work on a whole screen, the screen will turn black if you try that.

What does work is:

1. Create a view (in your main view), and hide all sensitive stuff in there. see image below

2. Use something like this

// Register that view as outlet.
    @IBOutlet var view1: UIView!

// Hide the outlet
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        self.view1.preventScreenshot()
    }

Hope this helps :)