Android: Decode images causes GC_FOR_ALLOC all time

Question

When i try to an image decode with BitmapFactory it cause GC_FOR_ALLOC all the time, and then the application crashed OutOfMemory.

Any suggestion for fix it? I need to solve this problem for a GridView with a lot of images (381 images 90k each one).

My code from AsyncTask:

@Override
        protected Bitmap doInBackground(Integer... params) {
            data = params[0];
            final Bitmap bitmap = decodeSampledBitmapFromResource(
                    context.getResources(), data, 100, 100);
            addBitmapToMemoryCache(String.valueOf(params[0]), bitmap);
            return bitmap;
        }

And my decodeSampledBitmapFromResource method:

public static Bitmap decodeSampledBitmapFromResource(Resources res,
            int resId, int reqWidth, int reqHeight) {

        // First decode with inJustDecodeBounds=true to check dimensions
        final BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeResource(res, resId, options);

        // Calculate inSampleSize
        options.inSampleSize = calculateInSampleSize(options, reqWidth,
                reqHeight);

        // Decode bitmap with inSampleSize set
        options.inJustDecodeBounds = false;
        return BitmapFactory.decodeResource(res, resId, options);
    }

Answer 1

If they are the same size you can resize into an unused old bitmap (you'll need to keep a referance counter so you can know when it's no longer in use by the gridview).

See https://developer.android.com/training/displaying-bitmaps/manage-memory.html

Also if you run out of memory with the code you have now your memory cache is likely too big... Use a heap dump or something like it to find out whats leaking.