当FlexBoxLayoutManger设置为RecyclerView的layoutManager时，如何计算行数

FlexBoxLayoutManager layoutManager = new FlexBoxLayoutManager(context);
recyclerView.setLayoutManager(layoutManager);

// 获取适配器对象
RecyclerView.Adapter adapter = recyclerView.getAdapter();

// 获取RecyclerView的宽度
int recyclerViewWidth = recyclerView.getWidth();

// 获取每一项的宽度
View childView = layoutManager.getChildAt(0);
int childWidth = childView.getWidth();

// 计算每一行可以容纳的子项数量
int itemsPerRow = recyclerViewWidth / childWidth;

// 计算行数
int rowCount = (int) Math.ceil((double) adapter.getItemCount() / itemsPerRow);