recycleView滑动到顶部带动BottomSheetBehavior

可以通过监听RecyclerView的滑动事件来控制BottomSheet的状态。具体实现步骤如下：

1. 获取RecyclerView对象，设置滑动监听。

val recyclerView: RecyclerView = findViewById(R.id.recyclerView)
recyclerView.addOnScrollListener(object : RecyclerView.OnScrollListener() {
    override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
        super.onScrolled(recyclerView, dx, dy)
        // 滑动事件处理
    }
})

2. 判断RecyclerView是否滑动到顶部。

val isTop = !recyclerView.canScrollVertically(-1)

3. 获取BottomSheetBehavior对象，设置状态。

val bottomSheetLayout: LinearLayout = findViewById(R.id.bottomSheetLayout)
val bottomSheetBehavior = BottomSheetBehavior.from(bottomSheetLayout)
if (isTop) {
    bottomSheetBehavior.state = BottomSheetBehavior.STATE_EXPANDED
} else {
    bottomSheetBehavior.state = BottomSheetBehavior.STATE_COLLAPSED
}

完整示例代码如下：

val recyclerView: RecyclerView = findViewById(R.id.recyclerView)
recyclerView.addOnScrollListener(object : RecyclerView.OnScrollListener() {
    override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
        super.onScrolled(recyclerView, dx, dy)
        val isTop = !recyclerView.canScrollVertically(-1)
        val bottomSheetLayout: LinearLayout = findViewById(R.id.bottomSheetLayout)
        val bottomSheetBehavior = BottomSheetBehavior.from(bottomSheetLayout)
        if (isTop) {
            bottomSheetBehavior.state = BottomSheetBehavior.STATE_EXPANDED
        } else {
            bottomSheetBehavior.state = BottomSheetBehavior.STATE_COLLAPSED
        }
    }
})