Take screen screenshot Android api 26

Question

I'm trying to make a screenshot of an activity in android, I found many examples online, but none works properly. In my case with a broadcast-receiver I intercept a specific event, and I launch an activity and I need to make the screenshot of this activity? Does anyone have any advice?

PS. I have already imported all the permissions to be able to save the screens on the disk. I use android api 26.

code that I found online

    try {
        // image naming and path  to include sd card  appending name you choose for file
        View view = getWindow().getDecorView();
        view.setDrawingCacheEnabled(true);
        view.buildDrawingCache();
        Bitmap b1 = rootView.getDrawingCache();
        Rect frame = new Rect();
        getWindow().getDecorView().getWindowVisibleDisplayFrame(frame);
        int statusBarHeight = frame.top;

        //Find the screen dimensions to create bitmap in the same size.
        int width = getWindowManager().getDefaultDisplay().getWidth();
        int height = getWindowManager().getDefaultDisplay().getHeight();

        Bitmap b = Bitmap.createBitmap(b1, 0, statusBarHeight, width, height - statusBarHeight);

    } catch (Throwable e) {
        // Several error may come out with file handling or DOM
        e.printStackTrace();
    }

When the code reaches the line who try to create Bitmap b, return java null point exception, because b1 is null.

What does "none works properly" mean? What are your symptoms? When are you calling the code that is shown in your question? — CommonsWare, Feb 18 '18 at 13:34
return java null pointer exception, when I try to create Bitmap b — apollo9, Feb 18 '18 at 13:45

score 0 · Answer 1 · answered Feb 18 '18 at 14:26

0

As you're getting NPE creating bitmap I suppose you don't have rootView variable . I don't see it initialized , maybe you wanted to put there view.getDrawingCache();

Refer this working example of creating bitmap

// create bitmap screen capture
        View v1 = getWindow().getDecorView().getRootView();
        v1.setDrawingCacheEnabled(true);
        Bitmap bitmap = Bitmap.createBitmap(v1.getDrawingCache());
        v1.setDrawingCacheEnabled(false);

Check this thread. I think there're nice answers to you question

answered Feb 18 '18 at 14:26

Rainmaker

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Returns java.lang.NullPointerException: Attempt to invoke virtual method 'int android.graphics.Bitmap.getWidth()' on a null object reference, when it try to create Bitmap – apollo9 Feb 18 '18 at 14:40
You should debug and see which parameter of createBitmap is null, it could be because your methods of getting width and height are deprecated. It could cause a problem too – Rainmaker Feb 18 '18 at 15:02

Take screen screenshot Android api 26

1 Answers1