联系人列表

效果图：

 <RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="org.mobiletrain.letterindex.MainActivity">

    <ListView
        android:id="@+id/lv"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:paddingLeft="12dp"
        android:paddingRight="36dp"></ListView>

    <org.mobiletrain.letterindex.LetterIndexView
        android:id="@+id/letter_index_view"
        android:layout_width="36dp"
        android:layout_height="match_parent"
        android:layout_alignParentRight="true"/>

    <TextView
        android:id="@+id/show_letter_in_center"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:background="@drawable/voip_toast_bg"
        android:gravity="center"
        android:visibility="gone"/>
</RelativeLayout>

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

    <TextView
        android:id="@+id/show_letter"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="3dp"/>

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <ImageView
            android:id="@+id/userface"
            android:layout_width="72dp"
            android:layout_height="72dp"
            android:padding="12dp"
            android:src="@mipmap/ic_launcher"/>

        <TextView
            android:id="@+id/username"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_centerVertical="true"
            android:layout_marginLeft="36dp"
            android:layout_toRightOf="@id/userface"
            android:gravity="center"
            android:text="username"/>
    </RelativeLayout>
</LinearLayout>

public class MainActivity extends AppCompatActivity {

    private List<User> list;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        final ListView listView = (ListView) findViewById(R.id.lv);
        initData();
        final MyAdapter adapter = new MyAdapter(this, list);
        listView.setAdapter(adapter);
        TextView textView = (TextView) findViewById(R.id.show_letter_in_center);
        final LetterIndexView letterIndexView = (LetterIndexView) findViewById(R.id.letter_index_view);
        letterIndexView.setTextViewDialog(textView);
        letterIndexView.setUpdateListView(new LetterIndexView.UpdateListView() {
            @Override
            public void updateListView(String currentChar) {
                int positionForSection = adapter.getPositionForSection(currentChar.charAt(0));
                listView.setSelection(positionForSection);
            }
        });
        listView.setOnScrollListener(new AbsListView.OnScrollListener() {
            @Override
            public void onScrollStateChanged(AbsListView view, int scrollState) {

            }

            @Override
            public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
                int sectionForPosition = adapter.getSectionForPosition(firstVisibleItem);
                letterIndexView.updateLetterIndexView(sectionForPosition);
            }
        });
    }

    private void initData() {
        list = new ArrayList<>();
        String[] allUserNames = getResources().getStringArray(R.array.arrUsernames);
        for (String allUserName : allUserNames) {
            User user = new User();
            user.setUsername(allUserName);
            String convert = ChineseToPinyinHelper.getInstance().getPinyin(allUserName).toUpperCase();
            user.setPinyin(convert);
            String substring = convert.substring(0, 1);
            if (substring.matches("[A-Z]")) {
                user.setFirstLetter(substring);
            }else{
                user.setFirstLetter("#");
            }
            list.add(user);
        }
        Collections.sort(list, new Comparator<User>() {
            @Override
            public int compare(User lhs, User rhs) {
                if (lhs.getFirstLetter().contains("#")) {
                    return 1;
                } else if (rhs.getFirstLetter().contains("#")) {
                    return -1;
                }else{
                    return lhs.getFirstLetter().compareTo(rhs.getFirstLetter());
                }
            }
        });
    }
}

public class LetterIndexView extends View {
    //当前手指滑动到的位置
    private int choosedPosition = -1;
    //画文字的画笔
    private Paint paint;
    //右边的所有文字
    private String[] letters = new String[]{"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L",
            "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z", "#"};
    //页面正中央的TextView，用来显示手指当前滑动到的位置的文本
    private TextView textViewDialog;
    //接口变量，该接口主要用来实现当手指在右边的滑动控件上滑动时ListView能够跟着滚动
    private UpdateListView updateListView;

    public LetterIndexView(Context context) {
        this(context, null);
    }

    public LetterIndexView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public LetterIndexView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        paint = new Paint();
        paint.setAntiAlias(true);
        paint.setTextSize(24);
    }

    public void setTextViewDialog(TextView textViewDialog) {
        this.textViewDialog = textViewDialog;
    }

    @Override
    protected void onDraw(Canvas canvas) {
        int perTextHeight = getHeight() / letters.length;
        for (int i = 0; i < letters.length; i++) {
            if (i == choosedPosition) {
                paint.setColor(Color.RED);
            } else {
                paint.setColor(Color.BLACK);
            }
            canvas.drawText(letters[i], (getWidth() - paint.measureText(letters[i])) / 2, (i + 1) * perTextHeight, paint);
        }
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        int perTextHeight = getHeight() / letters.length;
        float y = event.getY();
        int currentPosition = (int) (y / perTextHeight);
        String letter = letters[currentPosition];
        switch (event.getAction()) {
            case MotionEvent.ACTION_UP:
                setBackgroundColor(Color.TRANSPARENT);
                if (textViewDialog != null) {
                    textViewDialog.setVisibility(View.GONE);
                }
                break;
            default:
                setBackgroundColor(Color.parseColor("#cccccc"));
                if (currentPosition > -1 && currentPosition < letters.length) {
                    if (textViewDialog != null) {
                        textViewDialog.setVisibility(View.VISIBLE);
                        textViewDialog.setText(letter);
                    }
                    if (updateListView != null) {
                        updateListView.updateListView(letter);
                    }
                    choosedPosition = currentPosition;
                }
                break;
        }
        invalidate();
        return true;
    }

    public void setUpdateListView(UpdateListView updateListView) {
        this.updateListView = updateListView;
    }

    public interface UpdateListView {
        public void updateListView(String currentChar);
    }

    public void updateLetterIndexView(int currentChar) {
        for (int i = 0; i < letters.length; i++) {
            if (currentChar == letters[i].charAt(0)) {
                choosedPosition = i;
                invalidate();
                break;
            }
        }
    }
}

/**
 * Java汉字转换为拼音
 * created by 王松
 */
public class ChineseToPinyinHelper {
    private static int[] pyvalue = new int[] { -20319, -20317, -20304, -20295,
            -20292, -20283, -20265, -20257, -20242, -20230, -20051, -20036,
            -20032, -20026, -20002, -19990, -19986, -19982, -19976, -19805,
            -19784, -19775, -19774, -19763, -19756, -19751, -19746, -19741,
            -19739, -19728, -19725, -19715, -19540, -19531, -19525, -19515,
            -19500, -19484, -19479, -19467, -19289, -19288, -19281, -19275,
            -19270, -19263, -19261, -19249, -19243, -19242, -19238, -19235,
            -19227, -19224, -19218, -19212, -19038, -19023, -19018, -19006,
            -19003, -18996, -18977, -18961, -18952, -18783, -18774, -18773,
            -18763, -18756, -18741, -18735, -18731, -18722, -18710, -18697,
            -18696, -18526, -18518, -18501, -18490, -18478, -18463, -18448,
            -18447, -18446, -18239, -18237, -18231, -18220, -18211, -18201,
            -18184, -18183, -18181, -18012, -17997, -17988, -17970, -17964,
            -17961, -17950, -17947, -17931, -17928, -17922, -17759, -17752,
            -17733, -17730, -17721, -17703, -17701, -17697, -17692, -17683,
            -17676, -17496, -17487, -17482, -17468, -17454, -17433, -17427,
            -17417, -17202, -17185, -16983, -16970, -16942, -16915, -16733,
            -16708, -16706, -16689, -16664, -16657, -16647, -16474, -16470,
            -16465, -16459, -16452, -16448, -16433, -16429, -16427, -16423,
            -16419, -16412, -16407, -16403, -16401, -16393, -16220, -16216,
            -16212, -16205, -16202, -16187, -16180, -16171, -16169, -16158,
            -16155, -15959, -15958, -15944, -15933, -15920, -15915, -15903,
            -15889, -15878, -15707, -15701, -15681, -15667, -15661, -15659,
            -15652, -15640, -15631, -15625, -15454, -15448, -15436, -15435,
            -15419, -15416, -15408, -15394, -15385, -15377, -15375, -15369,
            -15363, -15362, -15183, -15180, -15165, -15158, -15153, -15150,
            -15149, -15144, -15143, -15141, -15140, -15139, -15128, -15121,
            -15119, -15117, -15110, -15109, -14941, -14937, -14933, -14930,
            -14929, -14928, -14926, -14922, -14921, -14914, -14908, -14902,
            -14894, -14889, -14882, -14873, -14871, -14857, -14678, -14674,
            -14670, -14668, -14663, -14654, -14645, -14630, -14594, -14429,
            -14407, -14399, -14384, -14379, -14368, -14355, -14353, -14345,
            -14170, -14159, -14151, -14149, -14145, -14140, -14137, -14135,
            -14125, -14123, -14122, -14112, -14109, -14099, -14097, -14094,
            -14092, -14090, -14087, -14083, -13917, -13914, -13910, -13907,
            -13906, -13905, -13896, -13894, -13878, -13870, -13859, -13847,
            -13831, -13658, -13611, -13601, -13406, -13404, -13400, -13398,
            -13395, -13391, -13387, -13383, -13367, -13359, -13356, -13343,
            -13340, -13329, -13326, -13318, -13147, -13138, -13120, -13107,
            -13096, -13095, -13091, -13076, -13068, -13063, -13060, -12888,
            -12875, -12871, -12860, -12858, -12852, -12849, -12838, -12831,
            -12829, -12812, -12802, -12607, -12597, -12594, -12585, -12556,
            -12359, -12346, -12320, -12300, -12120, -12099, -12089, -12074,
            -12067, -12058, -12039, -11867, -11861, -11847, -11831, -11798,
            -11781, -11604, -11589, -11536, -11358, -11340, -11339, -11324,
            -11303, -11097, -11077, -11067, -11055, -11052, -11045, -11041,
            -11038, -11024, -11020, -11019, -11018, -11014, -10838, -10832,
            -10815, -10800, -10790, -10780, -10764, -10587, -10544, -10533,
            -10519, -10331, -10329, -10328, -10322, -10315, -10309, -10307,
            -10296, -10281, -10274, -10270, -10262, -10260, -10256, -10254 };
    public static String[] pystr = new String[] { "a", "ai", "an", "ang", "ao",
            "ba", "bai", "ban", "bang", "bao", "bei", "ben", "beng", "bi",
            "bian", "biao", "bie", "bin", "bing", "bo", "bu", "ca", "cai",
            "can", "cang", "cao", "ce", "ceng", "cha", "chai", "chan", "chang",
            "chao", "che", "chen", "cheng", "chi", "chong", "chou", "chu",
            "chuai", "chuan", "chuang", "chui", "chun", "chuo", "ci", "cong",
            "cou", "cu", "cuan", "cui", "cun", "cuo", "da", "dai", "dan",
            "dang", "dao", "de", "deng", "di", "dian", "diao", "die", "ding",
            "diu", "dong", "dou", "du", "duan", "dui", "dun", "duo", "e", "en",
            "er", "fa", "fan", "fang", "fei", "fen", "feng", "fo", "fou", "fu",
            "ga", "gai", "gan", "gang", "gao", "ge", "gei", "gen", "geng",
            "gong", "gou", "gu", "gua", "guai", "guan", "guang", "gui", "gun",
            "guo", "ha", "hai", "han", "hang", "hao", "he", "hei", "hen",
            "heng", "hong", "hou", "hu", "hua", "huai", "huan", "huang", "hui",
            "hun", "huo", "ji", "jia", "jian", "jiang", "jiao", "jie", "jin",
            "jing", "jiong", "jiu", "ju", "juan", "jue", "jun", "ka", "kai",
            "kan", "kang", "kao", "ke", "ken", "keng", "kong", "kou", "ku",
            "kua", "kuai", "kuan", "kuang", "kui", "kun", "kuo", "la", "lai",
            "lan", "lang", "lao", "le", "lei", "leng", "li", "lia", "lian",
            "liang", "liao", "lie", "lin", "ling", "liu", "long", "lou", "lu",
            "lv", "luan", "lue", "lun", "luo", "ma", "mai", "man", "mang",
            "mao", "me", "mei", "men", "meng", "mi", "mian", "miao", "mie",
            "min", "ming", "miu", "mo", "mou", "mu", "na", "nai", "nan",
            "nang", "nao", "ne", "nei", "nen", "neng", "ni", "nian", "niang",
            "niao", "nie", "nin", "ning", "niu", "nong", "nu", "nv", "nuan",
            "nue", "nuo", "o", "ou", "pa", "pai", "pan", "pang", "pao", "pei",
            "pen", "peng", "pi", "pian", "piao", "pie", "pin", "ping", "po",
            "pu", "qi", "qia", "qian", "qiang", "qiao", "qie", "qin", "qing",
            "qiong", "qiu", "qu", "quan", "que", "qun", "ran", "rang", "rao",
            "re", "ren", "reng", "ri", "rong", "rou", "ru", "ruan", "rui",
            "run", "ruo", "sa", "sai", "san", "sang", "sao", "se", "sen",
            "seng", "sha", "shai", "shan", "shang", "shao", "she", "shen",
            "sheng", "shi", "shou", "shu", "shua", "shuai", "shuan", "shuang",
            "shui", "shun", "shuo", "si", "song", "sou", "su", "suan", "sui",
            "sun", "suo", "ta", "tai", "tan", "tang", "tao", "te", "teng",
            "ti", "tian", "tiao", "tie", "ting", "tong", "tou", "tu", "tuan",
            "tui", "tun", "tuo", "wa", "wai", "wan", "wang", "wei", "wen",
            "weng", "wo", "wu", "xi", "xia", "xian", "xiang", "xiao", "xie",
            "xin", "xing", "xiong", "xiu", "xu", "xuan", "xue", "xun", "ya",
            "yan", "yang", "yao", "ye", "yi", "yin", "ying", "yo", "yong",
            "you", "yu", "yuan", "yue", "yun", "za", "zai", "zan", "zang",
            "zao", "ze", "zei", "zen", "zeng", "zha", "zhai", "zhan", "zhang",
            "zhao", "zhe", "zhen", "zheng", "zhi", "zhong", "zhou", "zhu",
            "zhua", "zhuai", "zhuan", "zhuang", "zhui", "zhun", "zhuo", "zi",
            "zong", "zou", "zu", "zuan", "zui", "zun", "zuo" };
    private StringBuilder buffer;
    private String resource;
    private static ChineseToPinyinHelper characterParser = new ChineseToPinyinHelper();

    public static ChineseToPinyinHelper getInstance() {
        return characterParser;
    }

    public String getResource() {
        return resource;
    }

    public void setResource(String resource) {
        this.resource = resource;
    }

    /** * 汉字转成ASCII码 * * @param chs * @return */
    private int getChsAscii(String chs) {
        int asc = 0;
        try {
            byte[] bytes = chs.getBytes("gb2312");
            if (bytes == null || bytes.length > 2 || bytes.length <= 0) {
                throw new RuntimeException("illegal resource string");
            }
            if (bytes.length == 1) {
                asc = bytes[0];
            }
            if (bytes.length == 2) {
                int hightByte = 256 + bytes[0];
                int lowByte = 256 + bytes[1];
                asc = (256 * hightByte + lowByte) - 256 * 256;
            }
        } catch (Exception e) {
            System.out
                    .println("ERROR:ChineseSpelling.class-getChsAscii(String chs)"
                            + e);
        }
        return asc;
    }

    /** * 单字解析 * * @param str * @return */
    public String convert(String str) {
        String result = null;
        int ascii = getChsAscii(str);
        if (ascii > 0 && ascii < 160) {
            result = String.valueOf((char) ascii);
        } else {
            for (int i = (pyvalue.length - 1); i >= 0; i--) {
                if (pyvalue[i] <= ascii) {
                    result = pystr[i];
                    break;
                }
            }
        }
        return result;
    }

    /** * 词组解析 * * @param chs * @return */
    public String getPinyin(String chs) {
        String key, value;
        buffer = new StringBuilder();
        for (int i = 0; i < chs.length(); i++) {
            key = chs.substring(i, i + 1);
            if (key.getBytes().length >= 2) {
                value = (String) convert(key);
                if (value == null) {
                    value = "unknown";
                }
            } else {
                value = key;
            }
            buffer.append(value);
        }
        return buffer.toString();
    }

    public String getSpelling() {
        return this.getPinyin(this.getResource());
    }

}

public class User {
    private int img;
    private String username;
    private String pinyin;
    private String firstLetter;

    public User() {
    }

    public String getFirstLetter() {
        return firstLetter;
    }

    public void setFirstLetter(String firstLetter) {
        this.firstLetter = firstLetter;
    }

    public int getImg() {
        return img;
    }

    public void setImg(int img) {
        this.img = img;
    }

    public String getPinyin() {
        return pinyin;
    }

    public void setPinyin(String pinyin) {
        this.pinyin = pinyin;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public User(String firstLetter, int img, String pinyin, String username) {
        this.firstLetter = firstLetter;
        this.img = img;
        this.pinyin = pinyin;
        this.username = username;
    }
}

public class MyAdapter extends BaseAdapter implements SectionIndexer {
    private List<User> list;
    private Context context;
    private LayoutInflater inflater;

    public MyAdapter(Context context, List<User> list) {
        this.context = context;
        this.list = list;
        inflater = LayoutInflater.from(context);
    }

    @Override
    public int getCount() {
        return list.size();
    }

    @Override
    public Object getItem(int position) {
        return list.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;
        if (convertView == null) {
            convertView = inflater.inflate(R.layout.listview_item, null);
            holder = new ViewHolder();
            holder.showLetter = (TextView) convertView.findViewById(R.id.show_letter);
            holder.username = (TextView) convertView.findViewById(R.id.username);
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }
        User user = list.get(position);
        holder.username.setText(user.getUsername());
        //获得当前position是属于哪个分组
        int sectionForPosition = getSectionForPosition(position);
        //获得该分组第一项的position
        int positionForSection = getPositionForSection(sectionForPosition);
        //查看当前position是不是当前item所在分组的第一个item
        //如果是，则显示showLetter，否则隐藏
        if (position == positionForSection) {
            holder.showLetter.setVisibility(View.VISIBLE);
            holder.showLetter.setText(user.getFirstLetter());
        } else {
            holder.showLetter.setVisibility(View.GONE);
        }
        return convertView;
    }

    @Override
    public Object[] getSections() {
        return new Object[0];
    }

    //传入一个分组值[A....Z],获得该分组的第一项的position
    @Override
    public int getPositionForSection(int sectionIndex) {
        for (int i = 0; i < list.size(); i++) {
            if (list.get(i).getFirstLetter().charAt(0) == sectionIndex) {
                return i;
            }
        }
        return -1;
    }

    //传入一个position，获得该position所在的分组
    @Override
    public int getSectionForPosition(int position) {
        return list.get(position).getFirstLetter().charAt(0);
    }

    class ViewHolder {
        TextView username, showLetter;
    }
}