Android tabLayout+recyclerView实现锚点定位的示例

private LinearLayoutManager manager;private String[] tabTxt = {"客厅", "卧室", "餐厅", "书房", "阳台", "儿童房"};//判读是否是recyclerView主动引起的滑动，true- 是，false- 否，由tablayout引起的private boolean isRecyclerScroll;//记录上一次位置，防止在同一内容块里滑动 重复定位到tablayoutprivate int lastPos;//用于recyclerView滑动到指定的位置private boolean canScroll;private int scrollToPosition;//tablayout设置标签for (int i = 0; i < tabTxt.length; i++) {  tabLayout.addTab(tabLayout.newTab().setText(tabTxt[i]));}//计算内容块所在的高度，全屏高度-状态栏高度-tablayout的高度(这里固定高度50dp)，用于recyclerView的最后一个item view填充高度int screenH = getScreenHeight();int statusBarH = getStatusBarHeight(this);int tabH = 50 * 3;int lastH = screenH - statusBarH - tabH;manager = new LinearLayoutManager(this);recyclerView.setLayoutManager(manager);recyclerView.setAdapter(new MyAdapter(this, tabTxt, lastH));@Overridepublic void onBindViewHolder(MyViewHolder holder, int position) {  holder.anchorView.setContentTxt(tabTxt[position]);  holder.anchorView.setAnchorTxt(tabTxt[position]);  //判断最后一个view  if (position == tabTxt.length - 1) {    if (holder.anchorView.getHeight() < lastH) {      LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);      params.height = lastH;      holder.anchorView.setLayoutParams(params);    }  }}

recyclerView.setOnTouchListener(new View.OnTouchListener() {  @Override  public boolean onTouch(View v, MotionEvent event) {    //当滑动由recyclerView触发时，isRecyclerScroll 置true    if (event.getAction() == MotionEvent.ACTION_DOWN) {      isRecyclerScroll = true;    }    return false;  }});recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {  @Override  public void onScrolled(RecyclerView recyclerView, int dx, int dy) {    super.onScrolled(recyclerView, dx, dy);    if (isRecyclerScroll) {      //第一个可见的view的位置，即tablayou需定位的位置      int position = manager.findFirstVisibleItemPosition();      if (lastPos != position) {        tabLayout.setScrollPosition(position, 0, true);      }      lastPos = position;    }  }});

tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {  @Override  public void onTabSelected(TabLayout.Tab tab) {    //点击标签，使recyclerView滑动，isRecyclerScroll置false    int pos = tab.getPosition();    isRecyclerScroll = false;    moveToPosition(manager, recyclerView, pos);  }  @Override  public void onTabUnselected(TabLayout.Tab tab) {  }  @Override  public void onTabReselected(TabLayout.Tab tab) {  }});public void moveToPosition(LinearLayoutManager manager, RecyclerView mRecyclerView, int position) {  // 第一个可见的view的位置  int firstItem = manager.findFirstVisibleItemPosition();  // 最后一个可见的view的位置  int lastItem = manager.findLastVisibleItemPosition();  if (position <= firstItem) {    // 如果跳转位置firstItem 之前(滑出屏幕的情况)，就smoothScrollToPosition可以直接跳转，    mRecyclerView.smoothScrollToPosition(position);  } else if (position <= lastItem) {    // 跳转位置在firstItem 之后，lastItem 之间（显示在当前屏幕），smoothScrollBy来滑动到指定位置    int top = mRecyclerView.getChildAt(position - firstItem).getTop();    mRecyclerView.smoothScrollBy(0, top);  } else {    // 如果要跳转的位置在lastItem 之后，则先调用smoothScrollToPosition将要跳转的位置滚动到可见位置    // 再通过onScrollStateChanged控制再次调用当前moveToPosition方法，执行上一个判断中的方法    mRecyclerView.smoothScrollToPosition(position);    scrollToPosition = position;    canScroll = true;  }}recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {  @Override  public void onScrollStateChanged(RecyclerView recyclerView, int newState) {    super.onScrollStateChanged(recyclerView, newState);    if (canScroll) {      canScroll = false;      moveToPosition(manager, recyclerView, scrollToPosition);    }  }});