How to disable screen capture in Android fragment?

问题

Is it possible to disable screen capture from a fragment? I know the below works for an Activity class

onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_SECURE,
                WindowManager.LayoutParams.FLAG_SECURE);
}

But what if I have a fragment which shows up on top of an activity. Can I somehow disable screen capture? I've tried to set the FLAG_SECURE in the onCreate() or onCreateView() method of the fragment, but it doesn't work. I'm still able to take screen shot. Only when I add the flag in parent activity I can disable it.

On a related note, say, I've a method in ParentActivity.java (which extends Activity)

public void disableScreenCapture() {
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_SECURE,
            WindowManager.LayoutParams.FLAG_SECURE);

}

And in my ChildFragment.java (which extends Fragment)

            public void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);
                ParentActivity parentActivity = (ParentActivity)getActivity();
                parentActivity.disableScreenCapture(); //doesn't work
        }
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
                ParentActivity parentActivity = (ParentActivity)getActivity();
                parentActivity.disableScreenCapture(); //doesn't work either
    }

Any ideas?

Thanks in advance

回答1:

Performing your disableScreenCapture() call in onResume, onCreateView or onActivityAttached in your Fragment should all work - they did for me. Performing that call in onActivityCreated might not work as I believe that hook is only called when the Activity is being re-created, after it's destroyed. However, I didn't try that one.

If performing that call in onCreateView isn't working for you, are you 100% certain that your Fragment is actually being added to the Activity?

For a DialogFragment it's slightly different:

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

A DialogFragment isn't a Dialog itself, but instead holds a reference to one and shows/dismisses it when the fragment is added and removed. Dialogs have their own Windows and must have the flag set individually.

回答2:

The below code worked for me.

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
    getActivity().getWindow().setFlags(LayoutParams.FLAG_SECURE, LayoutParams.FLAG_SECURE);
    Window window = getActivity().getWindow();
    WindowManager wm = getActivity().getWindowManager();
    wm.removeViewImmediate(window.getDecorView());
    wm.addView(window.getDecorView(), window.getAttributes());

}

来源：https://stackoverflow.com/questions/32573371/how-to-disable-screen-capture-in-android-fragment

标签

android

android-fragments

screenshot

layoutparams