Retrieving all Drawable resources from Resources object

Okay, this feels a bit hack-ish, but this is what I came up with via Reflection. (Note that resources is an instance of class android.content.res.Resources.)

final R.drawable drawableResources = new R.drawable();
final Class<R.drawable> c = R.drawable.class;
final Field[] fields = c.getDeclaredFields();

for (int i = 0, max = fields.length; i < max; i++) {
    final int resourceId;
    try {
        resourceId = fields[i].getInt(drawableResources);
    } catch (Exception e) {
        continue;
    }
    /* make use of resourceId for accessing Drawables here */
}

If anyone has a better solution that makes better use of Android calls I might not be aware of, I'd definitely like to see them!

i used getResources().getIdentifier to scan through sequentially named images in my resource folders. to be on a safe side, I decided to cache image ids when activity is created first time:

    private void getImagesIdentifiers() {

    int resID=0;        
    int imgnum=1;
    images = new ArrayList<Integer>();

    do {            
        resID=getResources().getIdentifier("img_"+imgnum, "drawable", "InsertappPackageNameHere");
        if (resID!=0)
            images.add(resID);
        imgnum++;
    }
    while (resID!=0);

    imageMaxNumber=images.size();
}