How do I prevent Android taking a screenshot when my app goes to the background?

Question

The app I\'m currently building has the requirement that the app has to prevent the OS to take a screenshot of the app when it\'s being pushed into the background for securi

Answer 1

Try FLAG_SECURE:

public class FlagSecureTestActivity extends Activity {
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    getWindow().setFlags(WindowManager.LayoutParams.FLAG_SECURE,
                         WindowManager.LayoutParams.FLAG_SECURE);

    setContentView(R.layout.main);
  }
}

This definitely secures against manual screenshots and automatic screenshots from the ICS recent-tasks history. It also secures against screen recording (e.g., apps using the media projection APIs).

UPDATE: it also secures against Now On Tap or other assistants on Android 6.0; they will not get access to the details of widgets and containers in your UI if the user brings up the assistant.

UPDATE #2: however, not everything in the activity will be protected. Any pop-up windows — Dialog, Spinner, AutoCompleteTextView, action bar overflow, etc. — will be insecure. You can fix the Dialog problem by calling getWindow() on it and setting FLAG_SECURE. The rest... gets tricky. See this blog post for more.

Answer 2

The solution provided by CommonsWare continues to be valid also in Lollipop.

Just a note, if you want to continue to not see snapshots in recent list for the entire app, ALL the implemented activities should specify in the onCreate() method the flag getWindow().addFlags(WindowManager.LayoutParams.FLAG_SECURE); before setContentView();

Otherwise a snapshot in the recent list will show the first activity without the flag if the user navigated through it.

Answer 3

Here is a solution for hiding content of an app by covering it with a splash screen when the app is put into the background. This is not using the FLAG_SECURE technique, I simply override the onPause and onResume methods of the screens and modify the view to show one that covers everything in the back.

https://stackoverflow.com/a/52976001/6686912

Answer 4

getWindow().setFlags(WindowManager.LayoutParams.FLAG_SECURE,
            WindowManager.LayoutParams.FLAG_SECURE);

this worked for me, it prevents from taking screenshot and also any inbuilt or third party recording application from recording screen.

Answer 5

This is work for me after adding these line into the onCreate before setContentView of every activity.

getWindow().setFlags(WindowManager.LayoutParams.FLAG_SECURE,     
WindowManager.LayoutParams.FLAG_SECURE);
setContentView(R.layout.activity_notification);

Answer 6

Be careful about using WindowManager.LayoutParams.FLAG_SECURE, on some devices (verified on Samsung Galaxy ACE, e.g. GT-S5830) this will make the view scrambled. Looks like a Samsung specific bug. I recommend the following:

if(android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.HONEYCOMB) {
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_SECURE, WindowManager.LayoutParams.FLAG_SECURE);
}

This is what a scrambled screen looks like:

This is working properly on ICS Samsung phones though, so I'm assuming problem is isolated to Gingerbread devices (or older).