How To Pass A Arraylist Between Activities

I have an ArrayList that I have populated using the method getBitmapFromAsset() and want to pass it via intent using a Bundle. However it allows me to pass other Arra

Solution 1:

Passing the bitmaps itself from one activity to another is very memory inefficient. It may be OK if your bitmaps are small size icons, but if they are large bitmaps, you may encounter out of memory exception.

Have you consider refactor this a little bit, e.g. Use a singleton that has a HashMap of Bitmap ID (or asset name) to WeakReference of the bitmap itself. This singleton, let's call it BitmapHelper, will auto reload the bitmap from the asset, if it has not yet been loaded or has been freed by the garbage collector.

After your have this BitmapHelper, then it's a matter of passing the bitmap id/asset name in a String Array to another activity. From the other activity, you could just access the bitmap from the BitmapHelper.

Solution 2:

Bitmap implements Parcelable by default.

Use Bundle.putParcelableArrayList(String key, ArrayList<? extends Parcelable> value):

ArrayList<Bitmap> bitmaps = new ArrayList<Bitmap>();
bitmaps.add(bitmap);
bundle.putParcelableArrayList("names", bitmaps);