GridLayoutManager分割线

要在 GridLayoutManager 中添加分割线，可以使用 RecyclerView.ItemDecoration 类来实现。以下是一个示例代码片段，可以在 GridLayoutManager 中添加分割线：

public class GridDividerItemDecoration extends RecyclerView.ItemDecoration {

    private int spacing;

    public GridDividerItemDecoration(int spacing) {
        this.spacing = spacing;
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        int position = parent.getChildAdapterPosition(view);
        int spanCount = ((GridLayoutManager) parent.getLayoutManager()).getSpanCount();
        int column = position % spanCount;

        outRect.top = spacing;
        outRect.bottom = spacing;
        outRect.left = spacing;
        outRect.right = spacing;

        if (position < spanCount) {
            outRect.top = 0;
        }

        if (column == 0) {
            outRect.left = 0;
        }

        if ((column + 1) == spanCount) {
            outRect.right = 0;
        }
    }
}

然后，在设置 RecyclerView 的 Adapter 之后，可以将分割线添加到 RecyclerView 上，如下所示：

int spacing = getResources().getDimensionPixelSize(R.dimen.grid_spacing);
recyclerView.addItemDecoration(new GridDividerItemDecoration(spacing));

其中，R.dimen.grid_spacing 是一个在 dimens.xml 文件中定义的尺寸值，表示每个格子之间的间距。你可以根据实际情况进行调整。