Android中RecycleView自定义网格分割线ItemDecoration

public class GridDividerItemDecoration extends RecyclerView.ItemDecoration {
    private final Paint paint;
    private final int dividerWidth;
    private final Context context;

    public GridDividerItemDecoration(Context context, int dividerWidthDp, int dividerColorResId) {
        this.context = context;
        this.dividerWidth = dpToPx(context, dividerWidthDp);
        paint = new Paint();
        paint.setColor(ContextCompat.getColor(context, dividerColorResId));
        paint.setStyle(Paint.Style.FILL);
    }

    @Override
    public void getItemOffsets(@NonNull Rect outRect, @NonNull View view, @NonNull RecyclerView parent, @NonNull RecyclerView.State state) {
        int position = parent.getChildAdapterPosition(view);
        if (position == RecyclerView.NO_POSITION) return;

        GridLayoutManager layoutManager = (GridLayoutManager) parent.getLayoutManager();
        int spanCount = layoutManager.getSpanCount();
        int itemCount = parent.getAdapter().getItemCount();

        boolean isLastColumn = (position + 1) % spanCount == 0;
        boolean isLastRow = position >= itemCount - (itemCount % spanCount == 0 ? spanCount : itemCount % spanCount);

        outRect.right = isLastColumn ? 0 : dividerWidth;
        outRect.bottom = isLastRow ? 0 : dividerWidth;
    }

    @Override
    public void onDraw(@NonNull Canvas canvas, @NonNull RecyclerView parent, @NonNull RecyclerView.State state) {
        GridLayoutManager layoutManager = (GridLayoutManager) parent.getLayoutManager();
        int spanCount = layoutManager.getSpanCount();

        for (int i = 0; i < parent.getChildCount(); i++) {
            View child = parent.getChildAt(i);
            int position = parent.getChildAdapterPosition(child);
            if (position == RecyclerView.NO_POSITION) return;

            int itemCount = parent.getAdapter().getItemCount();
            boolean isLastColumn = (position + 1) % spanCount == 0;
            boolean isLastRow = position >= itemCount - (itemCount % spanCount == 0 ? spanCount : itemCount % spanCount);

            // 右侧分割线
            if (!isLastColumn) {
                canvas.drawRect(
                        child.getRight(),
                        child.getTop(),
                        child.getRight() + dividerWidth,
                        child.getBottom(),
                        paint
                );
            }

            // 底部分割线
            if (!isLastRow) {
                canvas.drawRect(
                        child.getLeft(),
                        child.getBottom(),
                        child.getRight()+ dividerWidth,
                        child.getBottom() + dividerWidth,
                        paint
                );
            }
        }
    }

    private static int dpToPx(Context context, float dp) {
        return (int) (dp * context.getResources().getDisplayMetrics().density + 0.5f);
    }
}

代码由腾讯元宝deepseek生成+个人修正（绘制底部分割线时child.getRight()+ dividerWidth，否则分割线太粗时交点空心），使用方法如下：

recycleview.addItemDecoration(new GridDividerItemDecoration(this,10,R.color.line_gray));