NullPointerException when trying to take screenshot programmatically

Question

I need to take a screenshot which I was coding in my game result screen.

I used the following method that I found in StackOverflow:

public void TakeScreenShot(){
    Date now = new Date();
    android.text.format.DateFormat.format("yyyy-MM-dd_hh:mm:ss", now);

    try {
        String mPath = Environment.getExternalStorageDirectory().toString() + "/PICTURES/Screenshots/" + now + ".jpg";

        v1 = this.findViewById(android.R.id.content).getRootView();
        v1.setDrawingCacheEnabled(true);
        bitmap = Bitmap.createBitmap(v1.getDrawingCache());
        v1.setDrawingCacheEnabled(false);

        File imageFile = new File(mPath);

        FileOutputStream outputStream = new FileOutputStream(imageFile);
        int quality = 100;
        bitmap.compress(Bitmap.CompressFormat.JPEG, quality, outputStream);
        outputStream.flush();
        outputStream.close();

        Toast.makeText(this, "Screenshot OK", Toast.LENGTH_SHORT).show();

    } catch (Throwable e) {
        e.printStackTrace();
    }
}

but I'm getting NullPointerException at Bitmap.CreateBitmap.

My Bitmap and Views are global and I try to call method in OnCreate.

11-04 15:20:17.868 13569-13569/com.finger W/System.err: java.lang.NullPointerException

How can I solve this problem?

I FOUND SOLUTION!

I try to call takeScreenshot method in onCreate and always i got same result all different variation, but i try call method in "Share Button" click event, now its working. Thank you.

`v1` or `v1.getDrawingCache()` will be `null`. Check before use. Or you are mistaken in the actual code line. — greenapps, Nov 04 '16 at 12:42
Hello @greenapps, i check if statment and my v1.getDrwaingCache is return null everytime, but i got same result Unfortunately — A. Batuhan Özkaya, Nov 04 '16 at 13:04

score 0 · Answer 1 · answered Nov 04 '16 at 12:44

0

I faced this problem once. try using this

v.setDrawingCacheEnabled(true);


// Without it the view will have a dimension of 0,0 and the bitmap will  be null          
v.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 
        MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
v.layout(0, 0, v.getMeasuredWidth(), v.getMeasuredHeight()); 

v.buildDrawingCache(true);
Bitmap b = Bitmap.createBitmap(v.getDrawingCache());
v.setDrawingCacheEnabled(false);

answered Nov 04 '16 at 12:44

Manas Dadheech

98
6

I get NullPointerException in line 96, and my line 96: v1.setDrawingCacheEnabled(true); – A. Batuhan Özkaya Nov 04 '16 at 12:54
try these options : http://stackoverflow.com/a/8817003/1515467 – Manas Dadheech Nov 04 '16 at 13:01
Hello @Manas, I tried all of these options but everytime i got same result, CreateBitMap NullPointer. – A. Batuhan Özkaya Nov 04 '16 at 13:09

siddhesh · Answer 2 · 2016-11-04T13:05:05.800

0

Try this code:

  private void takeScreenshot() {
        Date now = new Date();
        android.text.format.DateFormat.format("yyyy-MM-dd_hh:mm:ss", now);

        try {
            // image naming and path  to include sd card  appending name you choose for file
            String mPath = Environment.getExternalStorageDirectory().toString() + "/" + now + ".jpg";

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

            File imageFile = new File(mPath);

            FileOutputStream outputStream = new FileOutputStream(imageFile);
            int quality = 100;
            bitmap.compress(Bitmap.CompressFormat.JPEG, quality, outputStream);
            outputStream.flush();
            outputStream.close();

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

And this is how you can open the recently generated image:

private void openScreenshot(File imageFile) {
    Intent intent = new Intent();
    intent.setAction(Intent.ACTION_VIEW);
    Uri uri = Uri.fromFile(imageFile);
    intent.setDataAndType(uri, "image/*");
    startActivity(intent);
}

If you want to use this on fragment view then use:

View v1 = getActivity().getWindow().getDecorView().getRootView();

instead of

View v1 = getWindow().getDecorView().getRootView();

edited Nov 04 '16 at 13:05

answered Nov 04 '16 at 12:46

siddhesh

563
1
9
15

It is the same code... – M.Waqas Pervez Nov 04 '16 at 12:47
I got same result. – A. Batuhan Özkaya Nov 04 '16 at 12:57
did you replace this line View v1 = getWindow().getDecorView().getRootView(); – siddhesh Nov 04 '16 at 12:59
I changed my method completely with your code, – A. Batuhan Özkaya Nov 04 '16 at 13:00
what's new error then – siddhesh Nov 04 '16 at 13:01
Same result, CreateBitMap NullPointerException – A. Batuhan Özkaya Nov 04 '16 at 13:03
Hello @siddhesh, i found the solution. i try to call takeScreenshot method in onCreate and always i got same result, but i try call method in "Share Button" click event, now its working. Thank you. – A. Batuhan Özkaya Nov 04 '16 at 13:16
Glad you solved it ... – siddhesh Nov 04 '16 at 13:17

NullPointerException when trying to take screenshot programmatically

2 Answers2