prevent screen capture in Android apps

Question

I was wondering if there is a way to detect through some "onXXXXX" call-back method or received broadcast if some other process is about to take a screen-shot of my app's display. For example if the SDK tools or some other screen capturing app performs a "Screen Capture", I would like to be notified and then decide if I should allow or disallow the screen capture.

If this is not possible is there a way to lock the display so no other process can screen capture my display?

Answer 1

This worked for me on a Samsung Tab 2 7"

Using the following approach, to simply add the FLAG_SECURE to the Window Flags

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

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

    setContentView(R.layout.main);
  }
}

with the caveat that you may need to change

LayoutParams

to

WindowManager.LayoutParams

Answer 2

There is no supported method to take a screenshot of another app on Android. The only ways involve either rooting or using the SDK, which both offer little to no chance of you either blocking or receiving notification of it. If another app takes your screenshot, it is by default using non-supported methods and can probably do as it pleases.

I'd like to clarify that I am not implying you shouldn't use any methods available to secure your app. I'm just letting you know that it is probably impossible to do so without using non-supported methods, and that even if you do use them you may not be 100% secure against screenshots.