Android

1. 监听思路

NestedScrollView 内嵌 RecyclerView 时，RecyclerView的滑动监听很大可能监听不到，所以我们只能通过对NestedScrollView的监听进行RecyclerView的滑动判断；

2. 基本布局

别问我为什么有这种布局，你也会遇到的；（通用布局）

<android.support.v4.widget.SwipeRefreshLayout        android:id="@+id/baseSwipeRefresh"        android:layout_width="match_parent"        android:layout_height="match_parent"        app:layout_behavior="@string/appbar_scrolling_view_behavior">        <android.support.v4.widget.NestedScrollView            android:id="@+id/baseViewContent"            android:layout_width="match_parent"            android:layout_height="match_parent"            android:fillViewport="true"            android:scrollbars="none"            app:layout_behavior="@string/appbar_scrolling_view_behavior">        <android.support.v7.widget.RecyclerView                android:id="@+id/baseViewPager"                android:layout_width="match_parent"                android:layout_height="match_parent"     app:layout_behavior="@string/appbar_scrolling_view_behavior">        </android.support.v4.widget.NestedScrollView>    </android.support.v4.widget.SwipeRefreshLayout>

这里注意 需要给 NestedScrollView 添加下面属性：

android:fillViewport="true"

---

3. RecyclerView 初始化

 //设置layoutManager        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(mContext);        // auto measure : true        linearLayoutManager.setSmoothScrollbarEnabled(true);        linearLayoutManager.setAutoMeasureEnabled(true);        linearLayoutManager.setOrientation(VERTICAL);        recyclerView.setLayoutManager(linearLayoutManager);        // 设置为 true        recyclerView.setHasFixedSize(true);         recyclerView.setItemAnimator(new DefaultItemAnimator());        // 设置为 false        recyclerView.setNestedScrollingEnabled(false);

---

4. NestedScrollView 滑动监听

mNestedScrollView.setOnScrollChangeListener(new NestedScrollView.OnScrollChangeListener() {            @Override            public void onScrollChange(NestedScrollView v, int scrollX, int scrollY, int oldScrollX, int oldScrollY) {                if (scrollY > oldScrollY) {                // 向下滑动                }                if (scrollY < oldScrollY) {                  // 向上滑动                }                if (scrollY == 0) {                   // 顶部                }                if (scrollY == (v.getChildAt(0).getMeasuredHeight() - v.getMeasuredHeight())) {                  // 底部                }            }        });

---

5. 结语

好吧，通过对 NestedScrollView 的监听，对RecyclerView的数据操作即可！

---

6. 题外话（一） RecyclerView的滑动监听

简单实现RecyclerView的监听

重写滑动监听事件

/**     * 重写RecyclerView.OnScrollListener 判断滑动向上，向下，顶部，底部     */    public static abstract class OnVerticalScrollListener extends RecyclerView.OnScrollListener {        @Override        public final void onScrolled(RecyclerView recyclerView, int dx, int dy) {            LogUtil.e("ddd" + dy);            if (!recyclerView.canScrollVertically(-1)) {                onScrolledToTop();            } else if (!recyclerView.canScrollVertically(1)) {                onScrolledToBottom();            } else if (dy < 0) {                onScrolledUp();            } else if (dy > 0) {                onScrolledDown();            }        }        //向上滑动        public void onScrolledUp() {        }        //向下滑动        public void onScrolledDown() {        }        //滑动底部        public void onScrolledToTop() {        }        //滑动顶部        public void onScrolledToBottom() {        }    }

使用

 protected RecyclerView.OnScrollListener getOnScrollListener() {        //上下滑动监听        return new OnVerticalScrollListener() {            @Override            public void onScrolledToBottom() {                if (!isLoading) {                    page++;                    onLoadNextPage(page);                    isLoading = true;                }            }        };    }

---

7. 题外话（二）RecyclerAdapter的数据改变监听

给 adapter 注册一个观察者，执行下面notifyxxx方法的时候，会调用方法；

• notifyDataSetChanged()
• notifyItemChanged()

adapter.registerAdapterDataObserver(new RecyclerView.AdapterDataObserver() {            @Override            public void onChanged() {                super.onChanged();                checkAdapterEmpty();            }            @Override            public void onItemRangeInserted(int positionStart, int itemCount) {                super.onItemRangeInserted(positionStart, itemCount);                checkAdapterEmpty();            }            @Override            public void onItemRangeRemoved(int positionStart, int itemCount) {                super.onItemRangeRemoved(positionStart, itemCount);                checkAdapterEmpty();            }        });

---

完