How to use android.support.v7.widget

 @SuppressWarnings("SuspiciousNameCombination")
 @Override
 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
  super.onMeasure(widthMeasureSpec, widthMeasureSpec);
 }
}

  @Override
  public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
    super.onScrolled(recyclerView, dx, dy);
  }
});

@Override
public void setAdapter(Adapter adapter) {
  super.setAdapter(adapter);
  if(adapter != null) {
    adapter.registerAdapterDataObserver(emptyObserver);
  }
  emptyObserver.onChanged();
}

@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
  super.onViewCreated(view, savedInstanceState);
  mRecyclerView.setItemAnimator(new DefaultItemAnimator());
  mRecyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
  mRecyclerView.addItemDecoration(new DividerItemDecoration(getContext(),DividerItemDecoration.VERTICAL));
  mRecyclerView.setAdapter(mAdapter = new BaseRecyclerAdapter<Void>(initData(), simple_list_item_2) {
    @Override
    protected void onBindViewHolder(SmartViewHolder holder, Void model, int position) {
      holder.text(android.R.id.text1, getString(R.string.item_example_number_title, position));
      holder.text(android.R.id.text2, getString(R.string.item_example_number_abstract, position));
      holder.textColorId(android.R.id.text2, R.color.colorTextAssistant);
    }
  });
}

/**
 * 配置 RecyclerView
 *
 * @param recyclerView
 * @param layoutManager
 */
public static void configRecyclerView(final RecyclerView recyclerView
    , RecyclerView.LayoutManager layoutManager) {
  recyclerView.setLayoutManager(layoutManager);
  //如果可以确定每个item的高度是固定的，设置这个选项可以提高性能
  recyclerView.setHasFixedSize(true);
  recyclerView.setItemAnimator(new DefaultItemAnimator());
}

private void setupUserProfileGrid() {
  final StaggeredGridLayoutManager layoutManager = new StaggeredGridLayoutManager(3, StaggeredGridLayoutManager.VERTICAL);
  rvUserProfile.setLayoutManager(layoutManager);
  rvUserProfile.setOnScrollListener(new RecyclerView.OnScrollListener() {
    @Override
    public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
      userPhotosAdapter.setLockedAnimations(true);
    }
  });
}

 @Override
 public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
  LinearLayoutManager layoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();

  int firstVisible = layoutManager.findFirstVisibleItemPosition();
  int visibleCount = Math.abs(firstVisible - layoutManager.findLastVisibleItemPosition());
  int itemCount = recyclerView.getAdapter().getItemCount();

  if (firstVisible != lastFirstVisible || visibleCount != lastVisibleCount
    || itemCount != lastItemCount) {
   scrollListener.onScroll(null, firstVisible, visibleCount, itemCount);
   lastFirstVisible = firstVisible;
   lastVisibleCount = visibleCount;
   lastItemCount = itemCount;
  }
 }
}

private int getSpanCount(RecyclerView parent) {
  // 列数
  int spanCount = -1;
  RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
  if (layoutManager instanceof GridLayoutManager) {
    spanCount = ((GridLayoutManager) layoutManager).getSpanCount();
  } else if (layoutManager instanceof StaggeredGridLayoutManager) {
    spanCount = ((StaggeredGridLayoutManager) layoutManager)
        .getSpanCount();
  }
  return spanCount;
}

  @Override
  public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
    super.onScrolled(recyclerView, dx, dy);
    firstVisibleItem = linearLayoutManager.findFirstVisibleItemPosition();
    lastVisibleItem = linearLayoutManager.findLastVisibleItemPosition();
    //这是滑动自动播放的代码
    if (!mFull) {
      scrollCalculatorHelper.onScroll(recyclerView, firstVisibleItem, lastVisibleItem, lastVisibleItem - firstVisibleItem);
    }
  }
});

  private int getOrientation(RecyclerView parent) {
    if (parent.getLayoutManager() instanceof LinearLayoutManager) {
      LinearLayoutManager layoutManager = (LinearLayoutManager) parent.getLayoutManager();
      return layoutManager.getOrientation();
    } else {
      throw new IllegalStateException(
          "DividerItemDecoration can only be used with a LinearLayoutManager.");
    }
  }
}

/**
 * Get the {@link android.support.v7.widget.RecyclerView.LayoutManager} for
 * the {@link RecyclerView}
 *
 * @return recyclerView
 */
public LinearLayoutManager getLayoutManager() {
  if (recyclerView != null) {
    return (LinearLayoutManager) recyclerView.getLayoutManager();
  } else {
    return null;
  }
}

@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
  super.onScrolled(recyclerView, dx, dy);
  lastVisibleItem = gridLayoutManager.findLastVisibleItemPosition();
}

@Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
  super.onScrollStateChanged(recyclerView, newState);
}

private void checkLibraryVersion() {
  try {
    super.getChildAdapterPosition(null);
  } catch (NoSuchMethodError e) {
    recyclerViewLibraryVersion = 21;
  }
}

@Override
public void notifyDatasetChanged() {
  super.notifyDataSetChanged();
}

private MaterialViewPagerHeader(Toolbar toolbar) {
  this.toolbar = toolbar;
  this.context = toolbar.getContext();
  this.toolbarLayout = (View) toolbar.getParent();
}

private void setTopPadding(int topPadding) {
  if (type == Type.TABLET || isTitleless) {
    return;
  }
  iconView.setPadding(
      iconView.getPaddingLeft(),
      topPadding,
      iconView.getPaddingRight(),
      iconView.getPaddingBottom()
  );
}

int getCurrentDisplayedIconColor() {
  Object tag = iconView.getTag(R.id.bb_bottom_bar_color_id);
  if (tag instanceof Integer) {
    return (int) tag;
  }
  return 0;
}

@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
  super.onViewCreated(view, savedInstanceState);
  mRecyclerView = (RecyclerView) view;
  mRecyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
  mRecyclerView.setItemAnimator(new DefaultItemAnimator());
  mRecyclerView.addItemDecoration(new DividerItemDecoration(getContext(),DividerItemDecoration.VERTICAL));
  mRecyclerView.setAdapter(mAdapter = new BaseRecyclerAdapter<Void>(initData(), simple_list_item_2) {
    @Override
    protected void onBindViewHolder(SmartViewHolder holder, Void model, int position) {
      holder.text(android.R.id.text1, getString(R.string.item_example_number_title, position));
      holder.text(android.R.id.text2, getString(R.string.item_example_number_abstract, position));
      holder.textColorId(android.R.id.text2, R.color.colorTextAssistant);
    }
  });
}

  @Override
  public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
    super.onScrolled(recyclerView, dx, dy);
    // Could hide open views here if you wanted. //
  }
};