compile 'com.android.support:recyclerview-v7:26.0.0-alpha1'compile files('libs/pinyin4j-2.5.0.jar')

public class MainActivity extends AppCompatActivity {  //參考網址：https://github.com/JanecineJohn/WeChatList  private RecyclerView contactList;  private String[] contactNames;  private LinearLayoutManager layoutManager;  private LetterView letterView;  private ContactAdapter adapter;  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    contactNames = new String[] {"安然","奧茲","德瑪","張三豐", "郭靖", "黃蓉", "黃老邪", "趙敏", "123", "天山童姥", "任我行", "于萬亭", "陳家洛", "韋小寶", "$6", "穆人清", "陳圓圓", "郭芙", "郭襄", "穆念慈", "東方不敗", "梅超風", "林平之", "林遠圖", "滅絕師太", "段譽", "鳩摩智"};    contactList = (RecyclerView) findViewById(R.id.contact_list);    letterView = (LetterView) findViewById(R.id.letter_view);    layoutManager = new LinearLayoutManager(this);    adapter = new ContactAdapter(this, contactNames);    contactList.setLayoutManager(layoutManager);    contactList.addItemDecoration(new DividerItemDecoration(this, DividerItemDecoration.VERTICAL_LIST));    contactList.setAdapter(adapter);    letterView.setCharacterListener(new LetterView.CharacterClickListener() {      @Override      public void clickCharacter(String character) {        layoutManager.scrollToPositionWithOffset(adapter.getScrollPosition(character),0);      }      @Override      public void clickArrow() {        layoutManager.scrollToPositionWithOffset(0,0);      }    });  }}（3）Contact類public class Contact implements Serializable {  private String mName;  private int mType;  public Contact(String name, int type) {    mName = name;    mType = type;  }  public String getmName() {    return mName;  }  public int getmType() {    return mType;  }}

public class ContactAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder>{  private LayoutInflater mLayoutInflater;  private Context mContext;  private String[] mContactNames; // 聯系人名稱字符串數組  private List<String> mContactList; // 聯系人名稱List（轉換成拼音）  private List<Contact> resultList; // 最終結果（包含分組的字母）  private List<String> characterList; // 字母List  public enum ITEM_TYPE {    ITEM_TYPE_CHARACTER,    ITEM_TYPE_CONTACT  }  public ContactAdapter(Context context, String[] contactNames) {    mContext = context;    mLayoutInflater = LayoutInflater.from(context);    mContactNames = contactNames;    handleContact();  }  private void handleContact() {    mContactList = new ArrayList<>();    Map<String, String> map = new HashMap<>();    for (int i = 0; i < mContactNames.length; i++) {      String pinyin = Utils.getPingYin(mContactNames[i]);      map.put(pinyin, mContactNames[i]);      mContactList.add(pinyin);    }    Collections.sort(mContactList, new ContactComparator());    resultList = new ArrayList<>();    characterList = new ArrayList<>();    for (int i = 0; i < mContactList.size(); i++) {      String name = mContactList.get(i);      String character = (name.charAt(0) + "").toUpperCase(Locale.ENGLISH);      if (!characterList.contains(character)) {        if (character.hashCode() >= "A".hashCode() && character.hashCode() <= "Z".hashCode()) { // 是字母          characterList.add(character);          resultList.add(new Contact(character, ITEM_TYPE.ITEM_TYPE_CHARACTER.ordinal()));        } else {          if (!characterList.contains("#")) {            characterList.add("#");            resultList.add(new Contact("#", ITEM_TYPE.ITEM_TYPE_CHARACTER.ordinal()));          }        }      }      resultList.add(new Contact(map.get(name), ITEM_TYPE.ITEM_TYPE_CONTACT.ordinal()));    }  }  @Override  public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {    if (viewType == ITEM_TYPE.ITEM_TYPE_CHARACTER.ordinal()) {      return new CharacterHolder(mLayoutInflater.inflate(R.layout.item_character, parent, false));    } else {      return new ContactHolder(mLayoutInflater.inflate(R.layout.item_contact, parent, false));    }  }  @Override  public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {    if (holder instanceof CharacterHolder) {      ((CharacterHolder) holder).mTextView.setText(resultList.get(position).getmName());    } else if (holder instanceof ContactHolder) {      ((ContactHolder) holder).mTextView.setText(resultList.get(position).getmName());    }  }  @Override  public int getItemViewType(int position) {    return resultList.get(position).getmType();  }  @Override  public int getItemCount() {    return resultList == null ? 0 : resultList.size();  }  public class CharacterHolder extends RecyclerView.ViewHolder {    TextView mTextView;    CharacterHolder(View view) {      super(view);      mTextView = (TextView) view.findViewById(R.id.character);    }  }  public class ContactHolder extends RecyclerView.ViewHolder {    TextView mTextView;    ContactHolder(View view) {      super(view);      mTextView = (TextView) view.findViewById(R.id.contact_name);    }  }  public int getScrollPosition(String character) {    if (characterList.contains(character)) {      for (int i = 0; i < resultList.size(); i++) {        if (resultList.get(i).getmName().equals(character)) {          return i;        }      }    }    return -1; // -1不會滑動  }}

public class ContactComparator implements Comparator<String> {  @Override  public int compare(String o1, String o2) {    int c1 = (o1.charAt(0) + "").toUpperCase().hashCode();    int c2 = (o2.charAt(0) + "").toUpperCase().hashCode();    boolean c1Flag = (c1 < "A".hashCode() || c1 > "Z".hashCode()); // 不是字母    boolean c2Flag = (c2 < "A".hashCode() || c2 > "Z".hashCode()); // 不是字母    if (c1Flag && !c2Flag) {      return 1;    } else if (!c1Flag && c2Flag) {      return -1;    }    return c1 - c2;  }}

public class DividerItemDecoration 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;  private Drawable mDivider;  private int mOrientation;  public DividerItemDecoration(Context context, int orientation) {    final TypedArray a = context.obtainStyledAttributes(ATTRS);    mDivider = a.getDrawable(0);    a.recycle();    setOrientation(orientation);  }  private void setOrientation(int orientation) {    if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST) {      throw new IllegalArgumentException("invalid orientation");    }    mOrientation = orientation;  }  @Override  public void onDraw(Canvas c, RecyclerView parent) {    if (mOrientation == VERTICAL_LIST) {      drawVertical(c, parent);    } else {      drawHorizontal(c, parent);    }  }//  @Override//  public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {//    //super.onDraw(c, parent, state);//    if (mOrientation == VERTICAL_LIST) {//      drawVertical(c, parent);//    } else {//      drawHorizontal(c, parent);//    }//  }  public 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);    }  }  public 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);    }  }  @Override  public void getItemOffsets(Rect outRect, int itemPosition, RecyclerView parent) {    if (mOrientation == VERTICAL_LIST) {      outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());    } else {      outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);    }  }//  @Override//  public 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);//    }//  }}

public class LetterView extends LinearLayout{  private Context mContext;  private CharacterClickListener mListener;  public LetterView(Context context,AttributeSet attrs) {    super(context, attrs);    mContext = context;//接收傳進來的上下文    setOrientation(VERTICAL);    initView();  }  private void initView(){    addView(buildImageLayout());    for (char i = 'A';i<='Z';i++){      final String character = i + "";      TextView tv = buildTextLayout(character);      addView(tv);    }    addView(buildTextLayout("#"));  }  private TextView buildTextLayout(final String character){    LinearLayout.LayoutParams layoutParams =        new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT,1);    TextView tv = new TextView(mContext);    tv.setLayoutParams(layoutParams);    tv.setGravity(Gravity.CENTER);    tv.setClickable(true);    tv.setText(character);    tv.setOnClickListener(new OnClickListener() {      @Override      public void onClick(View view) {        if (mListener != null){          mListener.clickCharacter(character);        }      }    });    return tv;  }  private ImageView buildImageLayout() {    LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT, 1);    ImageView iv = new ImageView(mContext);    iv.setLayoutParams(layoutParams);    iv.setBackgroundResource(R.mipmap.ic_launcher);    iv.setOnClickListener(new OnClickListener() {      @Override      public void onClick(View v) {        if (mListener != null) {          mListener.clickArrow();        }      }    });    return iv;  }  public void setCharacterListener(CharacterClickListener listener) {    mListener = listener;  }  public interface CharacterClickListener {    void clickCharacter(String character);    void clickArrow();  }}

public class Utils {  public static String getPingYin(String inputString) {    HanyuPinyinOutputFormat format = new HanyuPinyinOutputFormat();    format.setCaseType(HanyuPinyinCaseType.LOWERCASE);    format.setToneType(HanyuPinyinToneType.WITHOUT_TONE);    format.setVCharType(HanyuPinyinVCharType.WITH_V);    char[] input = inputString.trim().toCharArray();    String output = "";    try {      for (char curchar : input) {        if (java.lang.Character.toString(curchar).matches("[//u4E00-//u9FA5]+")) {          String[] temp = PinyinHelper.toHanyuPinyinStringArray(curchar, format);          output += temp[0];        } else {          output += java.lang.Character.toString(curchar);        }      }    } catch (BadHanyuPinyinOutputFormatCombination e) {      e.printStackTrace();    }    return output;  }}