public class PagerSnapHelperActivity extends Activity {

 /**
  * UI
  */
 // recycleView
 private RecyclerView mRecyclerView = null;
 // adapter
 private PagerSnapHelperAdapter mMyadapter = null;
 /**
  * 數(shù)據(jù)
  */
 //data
 private ArrayList<String> mDataList = new ArrayList<String>();

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.recycle_pager_activity);

  // -----------創(chuàng)建數(shù)據(jù)集-------------
  for (int i = 1; i < 100; i++) {
   mDataList.add("item" + i);
  }
  // 縱向List
  initUI();

 }

 public void initUI() {
  // ---RecyclerView---
  mRecyclerView = (RecyclerView) findViewById(R.id.recyclerview_vertical);
  mRecyclerView.setNestedScrollingEnabled(false);
  // PagerSnapHelper
  PagerSnapHelper snapHelper = new PagerSnapHelper() {
   // 在 Adapter的 onBindViewHolder 之后執(zhí)行
   @Override
   public int findTargetSnapPosition(RecyclerView.LayoutManager layoutManager, int velocityX, int velocityY) {
    // TODO 找到對應的Index
    Log.e("xiaxl: ", "---findTargetSnapPosition---");
    int targetPos = super.findTargetSnapPosition(layoutManager, velocityX, velocityY);
    Log.e("xiaxl: ", "targetPos: " + targetPos);

    Toast.makeText(PagerSnapHelperActivity.this, "滑到到 " + targetPos + "位置", Toast.LENGTH_SHORT).show();

    return targetPos;
   }

   // 在 Adapter的 onBindViewHolder 之后執(zhí)行
   @Nullable
   @Override
   public View findSnapView(RecyclerView.LayoutManager layoutManager) {
    // TODO 找到對應的View
    Log.e("xiaxl: ", "---findSnapView---");
    View view = super.findSnapView(layoutManager);
    Log.e("xiaxl: ", "tag: " + view.getTag());

    return view;
   }
  };
  snapHelper.attachToRecyclerView(mRecyclerView);
  // ---布局管理器---
  LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
  // 默認是Vertical (HORIZONTAL則為橫向列表)
  linearLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
  //
  mRecyclerView.setLayoutManager(linearLayoutManager);

  // TODO 這么寫是為了獲取RecycleView的寬高
  mRecyclerView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
   @Override
   public void onGlobalLayout() {
    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) {
     mRecyclerView.getViewTreeObserver().removeGlobalOnLayoutListener(this);
    } else {
     mRecyclerView.getViewTreeObserver().removeOnGlobalLayoutListener(this);
    }

    /**
     * 這么寫是為了獲取RecycleView的寬高
     */
    // 創(chuàng)建Adapter，并指定數(shù)據(jù)集
    mMyadapter = new PagerSnapHelperAdapter(mDataList, mRecyclerView.getWidth(), mRecyclerView.getHeight());
    // 設置Adapter
    mRecyclerView.setAdapter(mMyadapter);
   }
  });
 }
}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:orientation="vertical">

 <android.support.v7.widget.RecyclerView
  android:id="@+id/recyclerview_vertical"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:scrollbars="vertical" />

</RelativeLayout>

public class PagerSnapHelperAdapter extends RecyclerView.Adapter<PagerSnapHelperAdapter.ViewHolder> {

 // 數(shù)據(jù)集
 private ArrayList<String> mDataList;


 private int mWidth;
 private int mHeight;

 //
 public PagerSnapHelperAdapter(ArrayList<String> dataset, int width, int height) {
  super();
  this.mDataList = dataset;
  //
  mWidth = width;
  mHeight = height;
 }

 @Override
 public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) {
  Log.e("xiaxl: ", "---onCreateViewHolder---");
  // 創(chuàng)建一個View，簡單起見直接使用系統(tǒng)提供的布局，就是一個TextView
  View view = View.inflate(viewGroup.getContext(), R.layout.recycle_pager_item, null);


  View contentView = view.findViewById(R.id.add_btn);
  RelativeLayout.LayoutParams rl = (RelativeLayout.LayoutParams) contentView.getLayoutParams();
  rl.width = mWidth;
  rl.height = mHeight;
  contentView.setLayoutParams(rl);


  // 創(chuàng)建一個ViewHolder
  ViewHolder holder = new ViewHolder(view);
  return holder;
 }

 @Override
 public void onBindViewHolder(ViewHolder viewHolder, int position) {
  Log.e("xiaxl: ", "---onBindViewHolder---");

  // 綁定數(shù)據(jù)到ViewHolder上
  viewHolder.itemView.setTag(position);
  //
  viewHolder.mTextView.setText(position + " item");
 }

 @Override
 public int getItemCount() {
  return mDataList.size();
 }

 /**
  *
  */
 public static class ViewHolder extends RecyclerView.ViewHolder {

  public TextView mTextView;

  public ViewHolder(View itemView) {
   super(itemView);
   mTextView = (TextView) itemView.findViewById(R.id.add_btn);
  }
 }
}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="match_parent"
 android:layout_height="640dp"
 android:orientation="vertical">


 <TextView
  android:id="@+id/add_btn"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:background="#ff0000"
  android:gravity="center"
  android:text="添加Item"
  android:textSize="36dp" />

</RelativeLayout>