_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
  }()

}

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 :)