双层嵌套RecyclerView整屏滑动

1. 布局

<RelativeLayout
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:background="@mipmap/bg_aux_middle"
        app:layout_constraintBottom_toBottomOf="@+id/cl_chinese"
        app:layout_constraintDimensionRatio="0.653"
        app:layout_constraintHeight_percent="0.581"
        app:layout_constraintHorizontal_bias="0.05"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="@+id/cl_writing"
        app:layout_constraintVertical_bias="0"
        >

        <TextView
            android:id="@+id/tv_sync"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="@dimen/px_15"
            android:text="同步大讲堂"
            android:textColor="@color/white"
            android:layout_centerHorizontal="true"
            android:textSize="@dimen/sp_22"
            android:textStyle="bold" />

        <ImageView
            android:id="@+id/tv_sync_class_more"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentEnd="true"
            android:layout_alignParentBottom="true"
            android:layout_marginTop="@dimen/px_20"
            android:layout_marginEnd="@dimen/px_25"
            android:paddingBottom="@dimen/px_20"
            android:src="@mipmap/icon_sync_more" />

        <TextView
            android:id="@+id/tv_page_pre"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:layout_marginEnd="@dimen/px_50"
            android:layout_toLeftOf="@+id/tv_page_next"
            android:drawableLeft="@mipmap/icon_page_pre"
            android:drawablePadding="@dimen/px_5"
            android:gravity="center"
            android:paddingTop="@dimen/px_5"
            android:paddingBottom="@dimen/px_15"
            android:text="上一页"
            android:textColor="@color/white"
            android:textSize="@dimen/sp_18" />

        <TextView
            android:id="@+id/tv_page_next"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:layout_marginEnd="@dimen/px_50"
            android:layout_toLeftOf="@+id/tv_sync_class_more"
            android:drawableLeft="@mipmap/icon_page_next"
            android:drawablePadding="@dimen/px_5"
            android:gravity="center"
            android:paddingTop="@dimen/px_5"
            android:paddingBottom="@dimen/px_15"
            android:text="下一页"
            android:textColor="@color/white"
            android:textSize="@dimen/sp_18" />

        <androidx.recyclerview.widget.RecyclerView
            android:id="@+id/rv_sync"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_above="@id/tv_page_next"
            android:layout_below="@+id/tv_sync" />
    </RelativeLayout>

2. Activity中的代码 双层嵌套RecyclerView整屏滑动

 private val scrollDistance2NextPage = 50

    inner class CrossRvScrollListener : RecyclerView.OnScrollListener() {
        var preScrollState = 0
        var preY = 0f
        val SCREEN_HEIGHT = 1080//d60s
        override fun onScrollStateChanged(recyclerView: RecyclerView, newState: Int) {
            super.onScrollStateChanged(recyclerView, newState)
            val state = preScrollState
            preScrollState = newState
            if (newState == RecyclerView.SCROLL_STATE_DRAGGING) {
            }
            if (rv_sync.getChildAt(0) == null) return
            if (state == RecyclerView.SCROLL_STATE_IDLE && newState == RecyclerView.SCROLL_STATE_DRAGGING) {
                val position =
                    (rv_sync.layoutManager as LinearLayoutManager).findFirstVisibleItemPosition()
                preY = rv_sync.getChildAt(0).y - position * SCREEN_HEIGHT
            } else if (state == RecyclerView.SCROLL_STATE_DRAGGING && newState != RecyclerView.SCROLL_STATE_DRAGGING) {
                val position =
                    (rv_sync.layoutManager as LinearLayoutManager).findFirstVisibleItemPosition()
                val y: Float = rv_sync.getChildAt(0).y - position * SCREEN_HEIGHT
                val scrolledY = y - preY
                var newPosition = -10
                if (scrolledY < 0) { //向右
                    newPosition = if (scrolledY <= 0 - scrollDistance2NextPage) {
                        position + 1
                    } else {
                        position
                    }
                }
                if (scrolledY > 0) { //向左
                    newPosition = if (scrolledY < scrollDistance2NextPage) {
                        position + 1
                    } else {
                        position
                    }
                }
                if (newPosition != -10) {
                    rv_sync.smoothScrollToPosition(newPosition)
                }
            }
        }
    }

    private fun prePage() {
        val position = (rv_sync.layoutManager as LinearLayoutManager).findFirstVisibleItemPosition()
        if (position == 0) {
            ToastUtils.showShort("当前已是第一页")
            return
        }
        rv_sync.smoothScrollToPosition(position - 1)
    }

    private fun nextPage() {
        val position = (rv_sync.layoutManager as LinearLayoutManager).findFirstVisibleItemPosition()
        if (position == rv_sync.adapter?.itemCount!! - 1) {
            ToastUtils.showShort("当前已是最后一页")
            return
        }
        rv_sync.smoothScrollToPosition(position + 1)
    }