public class MDRvActivity extends AppCompatActivity {
String imgur2="http://images.rednet.cn/ArticleImage/2017/04/25/201716483007449.jpg";
String imgurl3="http://images.rednet.cn/ArticleImage/2017/04/25/2017167258494983.jpg";
String geyan="学历代表过去，能力代表现在，学习力代表将来";private RecyclerView mRecyclerView;private RecyclerView.Adapter mAdapter;private RecyclerView.LayoutManager mLayoutManager;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.recycle_mdrv);initData();initView();}private void initData() {mLayoutManager = new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false);mAdapter = new MyAdapter(getData());}private void initView() {//RecyclerView的控件id，获取RecyclerView的控件mRecyclerView = (RecyclerView) findViewById(R.id.my_recycler_view);// 设置布局管理器
        mRecyclerView.setLayoutManager(mLayoutManager);// 设置adapter
        mRecyclerView.setAdapter(mAdapter);mRecyclerView.addItemDecoration(new MyDividerItemDecoration(this, LinearLayoutManager.VERTICAL));}/*  private ArrayList<NewsListData> getData() {ArrayList<NewsListData> data = new ArrayList<NewsListData>();for(int i = 0; i < 10; i++) {NewsListData newsListData=new NewsListData(imgur2,geyan+i,"10-11推荐");data.add(newsListData);}return data;}*/protected List getData(){List mDatas = new ArrayList<String>();for (int i = 'A'; i < 'z'; i++){mDatas.add("" + (char) i);}return mDatas;}}

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder>{private List<String> mData;public MyAdapter(List data) {this.mData = data;}public void updateData(List data) {this.mData = data;notifyDataSetChanged();}@Overridepublic ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {// 实例化展示的viewView v = LayoutInflater.from(parent.getContext()).inflate(R.layout.my, parent, false);// 实例化viewholderViewHolder viewHolder = new ViewHolder(v);return viewHolder;}@Overridepublic void onBindViewHolder(ViewHolder holder, int position) {// 绑定数据
        holder.mTv.setText((CharSequence) mData.get(position));}@Overridepublic int getItemCount() {return mData == null ? 0 : mData.size();}public static class ViewHolder extends RecyclerView.ViewHolder {TextView mTv;public ViewHolder(View itemView) {super(itemView);mTv = (TextView) itemView.findViewById(R.id.item_tv);}}
}

public class MyDividerItemDecoration extends RecyclerView.ItemDecoration {private static final int[] ATTRS = new int[]{android.R.attr.listDivider};public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;/*** 用于绘制间隔样式*/private Drawable mDivider;/*** 列表的方向，水平/竖直*/private int mOrientation;public MyDividerItemDecoration(Context context, int orientation) {// 获取默认主题的属性final TypedArray a = context.obtainStyledAttributes(ATTRS);mDivider = a.getDrawable(0);a.recycle();setOrientation(orientation);}@Overridepublic void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {// 绘制间隔if (mOrientation == VERTICAL_LIST) {drawVertical(c, parent);} else {drawHorizontal(c, parent);}}@Overridepublic void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {if (mOrientation == VERTICAL_LIST) {outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());} else {outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);}}private void setOrientation(int orientation) {if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST) {throw new IllegalArgumentException("invalid orientation");}mOrientation = orientation;}/*** 绘制间隔*/private void drawVertical(Canvas c, RecyclerView parent) {final int left = parent.getPaddingLeft();final int right = parent.getWidth() - parent.getPaddingRight();final int childCount = parent.getChildCount();for (int i = 0; i < childCount; i++) {final View child = parent.getChildAt(i);final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();final int top = child.getBottom() + params.bottomMargin +Math.round(ViewCompat.getTranslationY(child));final int bottom = top + mDivider.getIntrinsicHeight();mDivider.setBounds(left, top, right, bottom);mDivider.draw(c);}}/*** 绘制间隔*/private void drawHorizontal(Canvas c, RecyclerView parent) {final int top = parent.getPaddingTop();final int bottom = parent.getHeight() - parent.getPaddingBottom();final int childCount = parent.getChildCount();for (int i = 0; i < childCount; i++) {final View child = parent.getChildAt(i);final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();final int left = child.getRight() + params.rightMargin +Math.round(ViewCompat.getTranslationX(child));final int right = left + mDivider.getIntrinsicHeight();mDivider.setBounds(left, top, right, bottom);mDivider.draw(c);}}
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"xmlns:tools="http://schemas.android.com/tools"android:orientation="vertical"android:layout_width="match_parent"android:layout_height="500px"android:layout_marginTop="100px"tools:ignore="MissingDefaultResource"><android.support.v7.widget.RecyclerViewandroid:id="@+id/my_recycler_view"android:scrollbars="vertical"android:layout_width="match_parent"android:layout_height="match_parent"/>
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout   xmlns:android="http://schemas.android.com/apk/res/android"xmlns:tools="http://schemas.android.com/tools"android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="50dp"tools:ignore="MissingDefaultResource">
<TextViewandroid:id="@+id/item_tv"android:layout_width="match_parent"android:layout_height="match_parent"android:gravity="center"/>
</LinearLayout>