RecycleView自定义分割线

class SpaceItemDecoration extends RecyclerView.ItemDecoration {
    int mSpace;

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        super.getItemOffsets(outRect, view, parent, state);
        outRect.left = mSpace;
        outRect.bottom = mSpace;
        if (parent.getChildAdapterPosition(view) == 0 || parent.getChildAdapterPosition(view) % 3 == 0) {
            outRect.left = 0;
            outRect.bottom = 0;
        }

    }

    public SpaceItemDecoration(int space) {
        this.mSpace = space;
    }
}