Search code examples
androidresourcesdrawableidentifier

set image resource drawable with a programmatic String

Using an array with a base adapter to populate a listview. There are over many optional drawables and so a switch case is highly inefficient. I've been trying to implement a two liner using getResources().getIdentifier() system but all attempts have failed returning resource id of 0 x 0000.

working code

            try {
                final ImageView star = convertView.findViewById(R.id.star);
                final JSONObject object = list.getJSONObject(i);
                switch (object.getString("star")){
                    case "a":
                        star.setImageResource(R.drawable.stara);
                        break;
                    case "b":
                        star.setImageResource(R.drawable.starb);
                        break;
                    case "c":
                        star.setImageResource(R.drawable.starc);
                        break;
                    case "d":
                        star.setImageResource(R.drawable.stard);
                        break;
                }

I'm needing something using something like this but getIdentifier() method 

final ImageView star = convertView.findViewById(R.id.star);
star.setImageDrawable(getActivity().getResources().getDrawable(getActivity().getResources().getIdentifier("star" + object.getString("star") + ".png", "drawable", getActivity().getPackageName())));

"star" + object.getString("star") + ".png" is the exact drawable name in resource folder (stara.png, starb.png, ....)

I keep getting this exception with getIdentifier() method

No package identifier when getting value for resource number 0x00000000

How to properly implement this or a better way using a programmatic string to determine the resource drawable name being set to an imageview?

Solution

  • You should be omitting the ".png". If you are looking for "stara.png", what you are trying to get is the idenfifier R.drawable.stara, so what you should have is

    getActivity().getResources().getIdentifier("star" + object.getString("star"), "drawable", getActivity().getPackageName())));