Prevent Screenshots in Android

For some reasons, we may want to prevent users from taking screenshots of our app. In Android, we can use WindowManager.LayoutParams.FLAG_SECURE to achieve this effect. In the code below, we only need to set WindowManager.LayoutParams.FLAG_SECURE in Activity.onCreate().

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        window.setFlags(
            WindowManager.LayoutParams.FLAG_SECURE,
            WindowManager.LayoutParams.FLAG_SECURE,
        )
    }
}

If the user takes a screenshot on the screen with WindowManager.LayoutParams.FLAG_SECURE set, the system will automatically display the message “The app doesn’t allow taking screenshots”.

After setting WindowManager.LayoutParams.FLAG_SECURE, you can also use the code below to clear this flag at any time.

window.clearFlags(WindowManager.LayoutParams.FLAG_SECURE)

Finally, it should be noted that this WindowManager.LayoutParams.FLAG_SECURE will only affect the current Activity. If you want to prevent screenshots for every Activity, you can set WindowManager.LayoutParams.FLAG_SECURE in ActivityLifecycleCallbacks.onActivityCreated().

class MyApplication : Application() {
    override fun onCreate() {
        super.onCreate()
   
        registerActivityLifecycleCallbacks(object : ActivityLifecycleCallbacks {
            override fun onActivityCreated(activity: Activity, savedInstanceState: Bundle?) {
                activity.window.setFlags(
                    WindowManager.LayoutParams.FLAG_SECURE,
                    WindowManager.LayoutParams.FLAG_SECURE
                )
            }

            override fun onActivityStarted(activity: Activity) {}
            override fun onActivityResumed(activity: Activity) {}
            override fun onActivityPaused(activity: Activity) {}
            override fun onActivityStopped(activity: Activity) {}
            override fun onActivitySaveInstanceState(activity: Activity, outState: Bundle) {}
            override fun onActivityDestroyed(activity: Activity) {}
        })
    }
}