java.lang.OutOfMemoryError: bitmap size exceeds VM budget - android - how many images?

Question

I am developing an android app and as I read all around and learned for myself, I cant have a lot of images on the screen at the same time or I will get an exception.

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Answer 1

One of the most common errors that I found developing Android Apps is the

java.lang.OutOfMemoryError: Bitmap Size Exceeds VM Budget error.

I found this error frequently on activities using lots of bitmaps after changing orientation: the Activity is destroyed, created again and the layouts are “inflated” from the XML consuming the VM memory available for bitmaps.

Bitmaps on the previous activity layout are not properly deallocated by the garbage collector because they have crossed references to their activity. After many experiments I found a quite good solution for this problem.

First, set the id attribute on the parent view of your XML layout:

    
    
     ...

Then, on the onDestroy() method of your Activity, call the unbindDrawables() method passing a refence to the parent View and then do a System.gc()

    @Override
    protected void onDestroy() {
    super.onDestroy();

    unbindDrawables(findViewById(R.id.RootView));
    System.gc();
    }

    private void unbindDrawables(View view) {
        if (view.getBackground() != null) {
        view.getBackground().setCallback(null);
        }
        if (view instanceof ViewGroup) {
            for (int i = 0; i < ((ViewGroup) view).getChildCount(); i++) {
            unbindDrawables(((ViewGroup) view).getChildAt(i));
            }
        ((ViewGroup) view).removeAllViews();
        }
    }

This unbindDrawables() method explores the view tree recursively and:

• Removes callbacks on all the background drawables
• Removes childs on every viewgroup