Code to detect when a user perform a screen capture or screen recording of an application in order to prevent it when possible

ios-detect-screen-capture-and-screen-recording.swift

import UIKit

//Inspired from the code below:
//https://github.com/takashings/ScreenCapturedSample/blob/master/ScreenCapturedSample/ForScreenCapturedViewController.swift
//https://www.hackingwithswift.com/example-code/uikit/how-to-detect-when-the-user-takes-a-screenshot
@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
    
    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        //Define a listener to handle the case when a screen recording is launched
        //for example using the iPhone built-in feature
        NotificationCenter.default.addObserver(
            self,
            selector: #selector(didScreenRecording(_:)),
            name: UIScreen.capturedDidChangeNotification,
            object: nil
        )

        //Define a listener to handle the case when a screenshot is performed
        //Unfortunately screenshot cannot be prevented but just detected...
        NotificationCenter.default.addObserver(
            self,
            selector: #selector(didScreenshot(_:)),
            name: UIApplication.userDidTakeScreenshotNotification,
            object: nil)
        return true
    }
    
    @objc private func didScreenshot(_ notification: Notification) {
        #if DEBUG
        //Never add this log in RELEASED app.
        print("Screen capture detected then we force the immediate exit of the app!")
        #endif
        //Information about the image is not available here and screenshot cannot be prevented AS IS
        //See hint here about a way to address this issue:
        //https://tumblr.jeremyjohnstone.com/post/38503925370/how-to-detect-screenshots-on-ios-like-snapchat
        //In all case: Send notification to the backend and clear all local data/secret from the storage/keychain
        exit(0)
    }
    
    @objc private func didScreenRecording(_ notification: Notification) {
        //If a screen recording operation is pending then we close the application
        print(UIScreen.main.isCaptured)
        if UIScreen.main.isCaptured {
            #if DEBUG
            //Never add this log in RELEASED app.
            print("Screen recording detected then we force the immediate exit of the app!")
            #endif
            exit(0)
        }
    }
    
    // MARK: UISceneSession Lifecycle
    
    func application(_ application: UIApplication, configurationForConnecting connectingSceneSession: UISceneSession, options: UIScene.ConnectionOptions) -> UISceneConfiguration {
        // Called when a new scene session is being created.
        // Use this method to select a configuration to create the new scene with.
        return UISceneConfiguration(name: "Default Configuration", sessionRole: connectingSceneSession.role)
    }
    
    func application(_ application: UIApplication, didDiscardSceneSessions sceneSessions: Set<UISceneSession>) {
        // Called when the user discards a scene session.
        // If any sessions were discarded while the application was not running, this will be called shortly after application:didFinishLaunchingWithOptions.
        // Use this method to release any resources that were specific to the discarded scenes, as they will not return.
    }   
}

Any idea how one would implement the notes in https://tumblr.jeremyjohnstone.com/post/38503925370/how-to-detect-screenshots-on-ios-like-snapchat ?

I want to achieve the same effect that WhatsApp has for View Once photos, which is to add an overlay over sensitive content when the user takes a screenshot

Hi,

Honestly I do not know how to achieve such behavior.