AnimationDrawable动画图片资源回收

private static void tryRecycleAnimationDrawable(AnimationDrawable animationDrawable) {

	if (animationDrawable != null) {

        animationDrawable.stop();
        for (int i = 0; i < animationDrawable.getNumberOfFrames(); i++) {
            Drawable frame = animationDrawable.getFrame(i);
            if (frame instanceof BitmapDrawable) {
                ((BitmapDrawable) frame).getBitmap().recycle();
            }
            frame.setCallback(null);
        }
        animationDrawable.setCallback(null);
    }
}

取出AnimationDrawable中的每一帧逐个回收，并且设置Callback为null。