1、:recyclerview依赖

这个v7:28.0.0是根据自己android studio 依赖中: implementation 'com.android.support:appcompat-v7:28.0.0'  ,版本是一样的。
即: implementation 'com.android.support:recyclerview-v7:28.0.0'

2、SideBar

public class SideBar extends View {
    // 触摸事件
    private OnTouchingLetterChangedListener onTouchingLetterChangedListener;
    // 26个字母
    public static String[] b = { "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", "#" };
    private int choose = -1;// 选中
    private Paint paint = new Paint();

    private TextView mTextDialog;

    public void setTextView(TextView mTextDialog) {
        this.mTextDialog = mTextDialog;
    }

    public SideBar(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    public SideBar(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public SideBar(Context context) {
        super(context);
    }

    /**
     * 重写这个方法
     */
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        // 获取焦点改变背景颜色.
        int height = getHeight();// 获取对应高度
        int width = getWidth(); // 获取对应宽度
        int singleHeight = height / b.length;// 获取每一个字母的高度

        for (int i = 0; i < b.length; i++) {
            paint.setColor(Color.rgb(33, 65, 98));
            // paint.setColor(Color.WHITE);
            paint.setTypeface(Typeface.DEFAULT_BOLD);
            paint.setAntiAlias(true);
            paint.setTextSize(20);
            // 选中的状态
            if (i == choose) {
                paint.setColor(Color.parseColor("#3399ff"));
                paint.setFakeBoldText(true);
            }
            // x坐标等于中间-字符串宽度的一半.
            float xPos = width / 2 - paint.measureText(b[i]) / 2;
            float yPos = singleHeight * i + singleHeight;
            canvas.drawText(b[i], xPos, yPos, paint);
            paint.reset();// 重置画笔
        }

    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent event) {
        final int action = event.getAction();
        final float y = event.getY();// 点击y坐标
        final int oldChoose = choose;
        final OnTouchingLetterChangedListener listener = onTouchingLetterChangedListener;
        final int c = (int) (y / getHeight() * b.length);// 点击y坐标所占总高度的比例*b数组的长度就等于点击b中的个数.

        switch (action) {
            case MotionEvent.ACTION_UP:
                setBackgroundDrawable(new ColorDrawable(0x00000000));
                choose = -1;//
                invalidate();
                if (mTextDialog != null) {
                    mTextDialog.setVisibility(View.INVISIBLE);
                }
                break;

            default:
                // 设置右侧字母列表[A,B,C,D,E....]的背景颜色
                setBackgroundResource(R.mipmap.bg);
                if (oldChoose != c) {
                    if (c >= 0 && c < b.length) {
                        if (listener != null) {
                            listener.onTouchingLetterChanged(b[c]);
                        }
                        if (mTextDialog != null) {
                            mTextDialog.setText(b[c]);
                            mTextDialog.setVisibility(View.VISIBLE);
                        }

                        choose = c;
                        invalidate();
                    }
                }

                break;
        }
        return true;
    }

    /**
     * 向外公开的方法
     *
     * @param onTouchingLetterChangedListener
     */
    public void setOnTouchingLetterChangedListener(OnTouchingLetterChangedListener onTouchingLetterChangedListener) {
        this.onTouchingLetterChangedListener = onTouchingLetterChangedListener;
    }

    /**
     * 接口
     *
     * @author coder
     *
     */
    public interface OnTouchingLetterChangedListener {
        public void onTouchingLetterChanged(String s);
    }

}

3、main

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    private ListView sortListView;
    private SideBar sideBar;
    private TextView dialog;
    private SortAdapter adapter;

    /**
     * 汉字转换成拼音的类
     */
    private CharacterParser characterParser;
    private List<SortModel> SourceDateList;

    /**
     * 根据拼音来排列ListView里面的数据类
     */
    private PinyinComparator pinyinComparator;
//    private ImageView mBackImg;
//    /**
//     * 返回
//     */
//    private TextView mBack;
//    /**
//     * 设置
//     */
//    private TextView mSet;
//    /**
//     * 保存
//     */
//    private TextView mSave;
    //默认是false
    private boolean flag;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();

        initData();
    }
    private void initData() {

        //选择好友进行PKtextView的切换与隐藏的点击事件
//        mSave.setOnClickListener(new View.OnClickListener() {
//            @Override
//            public void onClick(View view) {
//                if(!flag){//编辑 -> 完成
//                    flag=true;
//                    mSave.setText("完成");
//                    adapter.showCheckBox(flag);
//                }else{
//                    flag=false;
//                    mSave.setText("添加");
//                    adapter.showCheckBox(flag);
//                }
//            }
//        });



    }

    public void initView() {
        // 实例化汉字转拼音类
        characterParser = CharacterParser.getInstance();

        pinyinComparator = new PinyinComparator();

        sideBar = (SideBar) findViewById(R.id.sidrbar);
        dialog = (TextView) findViewById(R.id.dialog);
        sideBar.setTextView(dialog);

        // 设置右侧触摸监听
        sideBar.setOnTouchingLetterChangedListener(new SideBar.OnTouchingLetterChangedListener() {

            @Override
            public void onTouchingLetterChanged(String s) {
                // 该字母首次出现的位置
                int position = adapter.getPositionForSection(s.charAt(0));
                if (position != -1) {
                    sortListView.setSelection(position);
                }

            }
        });

        sortListView = (ListView) findViewById(R.id.country_lvcountry);
        sortListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                // 这里要利用adapter.getItem(position)来获取当前position所对应的对象
                Toast.makeText(getApplication(), ((SortModel) adapter.getItem(position)).getName(), Toast.LENGTH_SHORT).show();
            }
        });

        SourceDateList = filledData(getResources().getStringArray(R.array.date));

        // 根据a-z进行排序源数据
        Collections.sort(SourceDateList, pinyinComparator);
        adapter = new SortAdapter(getApplicationContext(), SourceDateList);
        sortListView.setAdapter(adapter);


    }

    /**
     * 为ListView填充数据
     *
     * @param date
     * @return
     */
    private List<SortModel> filledData(String[] date) {
        List<SortModel> mSortList = new ArrayList<SortModel>();

        for (int i = 0; i < date.length; i++) {
            SortModel sortModel = new SortModel();
            sortModel.setName(date[i]);
            // 汉字转换成拼音
            String pinyin = characterParser.getSelling(date[i]);
            String sortString = pinyin.substring(0, 1).toUpperCase();

            // 正则表达式,判断首字母是否是英文字母
            if (sortString.matches("[A-Z]")) {
                sortModel.setSortLetters(sortString.toUpperCase());
            } else {
                sortModel.setSortLetters("#");
            }

            mSortList.add(sortModel);
        }
        return mSortList;

    }

    /**
     * 根据输入框中的值来过滤数据并更新ListView
     *
     * @param filterStr
     */
    private void filterData(String filterStr) {
        List<SortModel> filterDateList = new ArrayList<SortModel>();

        if (TextUtils.isEmpty(filterStr)) {
            filterDateList = SourceDateList;
        } else {
            filterDateList.clear();
            for (SortModel sortModel : SourceDateList) {
                String name = sortModel.getName();
                if (name.indexOf(filterStr.toString()) != -1 || characterParser.getSelling(name).startsWith(filterStr.toString())) {
                    filterDateList.add(sortModel);
                }
            }
        }

        // 根据a-z进行排序
        Collections.sort(filterDateList, pinyinComparator);
        adapter.updateListView(filterDateList);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            default:
                break;

        }
    }
}

4、SortAdapter

public class SortAdapter extends BaseAdapter implements SectionIndexer {
    private Context mContext;
    private List<SortModel> list = null;


    public SortAdapter(Context mContext, List<SortModel> list) {
        this.mContext = mContext;
        this.list = list;
    }

    //接收是否处于编辑状态的一个boolean值
    private boolean isEditor;
    public void showCheckBox(boolean isEditor){
        this.isEditor=isEditor;
        //刷新适配器
        notifyDataSetChanged();
    }

    /**
     * 当ListView数据发生变化时,调用此方法来更新ListView
     *
     * @param list
     */
    public void updateListView(List<SortModel> list) {
        this.list = list;
        notifyDataSetChanged();
    }

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

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

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

    public View getView(final int position, View view, ViewGroup arg2) {
        ViewHolder viewHolder = null;
        final SortModel mContent = list.get(position);
        if (view == null) {
            viewHolder = new ViewHolder();
            view = LayoutInflater.from(mContext).inflate(R.layout.item_sort_listview, null);
            viewHolder.tvTitle = (TextView) view.findViewById(R.id.title);
            viewHolder.tvLetter = (TextView) view.findViewById(R.id.catalog);
            viewHolder.check_item = (CheckBox) view.findViewById(R.id.check_item);
            view.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) view.getTag();
        }

        // 根据position获取分类的首字母的Char ascii值
        int section = getSectionForPosition(position);

        // 如果当前位置等于该分类首字母的Char的位置 ,则认为是第一次出现
        if (position == getPositionForSection(section)) {
            viewHolder.tvLetter.setVisibility(View.VISIBLE);
            viewHolder.tvLetter.setText(mContent.getSortLetters());
        } else {
            viewHolder.tvLetter.setVisibility(View.GONE);
        }

        viewHolder.tvTitle.setText(this.list.get(position).getName());



        //控制删除按钮的隐藏与显示
        if(isEditor){
            viewHolder.check_item.setVisibility(View.VISIBLE);
        }else{
            viewHolder.check_item.setVisibility(View.GONE);
            viewHolder.check_item.setChecked(false);
        }




        return view;

    }

    final static class ViewHolder {
        TextView tvLetter;
        TextView tvTitle;
        CheckBox check_item;
    }

    /**
     * 根据ListView的当前位置获取分类的首字母的Char ascii值
     */
    public int getSectionForPosition(int position) {
        return list.get(position).getSortLetters().charAt(0);
    }

    /**
     * 根据分类的首字母的Char ascii值获取其第一次出现该首字母的位置
     */
    public int getPositionForSection(int section) {
        for (int i = 0; i < getCount(); i++) {
            String sortStr = list.get(i).getSortLetters();
            char firstChar = sortStr.toUpperCase().charAt(0);
            if (firstChar == section) {
                return i;
            }
        }

        return -1;
    }

    /**
     * 提取英文的首字母,非英文字母用#代替。
     *
     * @param str
     * @return
     */
    private String getAlpha(String str) {
        String sortStr = str.trim().substring(0, 1).toUpperCase();
        // 正则表达式,判断首字母是否是英文字母
        if (sortStr.matches("[A-Z]")) {
            return sortStr;
        } else {
            return "#";
        }
    }

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

5、CharacterParser

public class CharacterParser {
    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 CharacterParser characterParser = new CharacterParser();

    public static CharacterParser 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 getSelling(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.getSelling(this.getResource());
    }
}

6、SortModel

public class SortModel {
    private String name; // 显示的数据
    private String sortLetters; // 显示数据拼音的首字母

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getSortLetters() {
        return sortLetters;
    }

    public void setSortLetters(String sortLetters) {
        this.sortLetters = sortLetters;
    }
}

7、PinyinComparator

public class PinyinComparator implements Comparator<SortModel> {

    public int compare(SortModel o1, SortModel o2) {
        if (o1.getSortLetters().equals("@")
                || o2.getSortLetters().equals("#")) {
            return -1;
        } else if (o1.getSortLetters().equals("#")
                || o2.getSortLetters().equals("@")) {
            return 1;
        } else {
            return o1.getSortLetters().compareTo(o2.getSortLetters());
        }
    }

}

8、values文件夹下的array.data

<?xml version="1.0" encoding="UTF-8"?>
<resources>

    <string-array name="date">
        <item>Peter</item>
        <item>Allen</item>
        <item>阿妹</item>
        <item>阿郎</item>
        <item>陈奕迅</item>
        <item>周杰伦</item>
        <item>曾一鸣</item>
        <item>成龙</item>
        <item>王力宏</item>
        <item>汪峰</item>
        <item>王菲</item>
        <item>那英</item>
        <item>张伟</item>
        <item>张学友</item>
        <item>李德华</item>
        <item>郑源</item>
        <item>白水水</item>
        <item>白天不亮</item>
        <item>陈龙</item>
        <item>陈丽丽</item>
        <item>哈林</item>
        <item>高进</item>
        <item>高雷</item>
        <item>阮今天</item>
        <item>龚琳娜</item>
        <item>苏醒</item>
        <item>苏永康</item>
        <item>陶喆</item>
        <item>沙宝亮</item>
        <item>宋冬野</item>
        <item>宋伟</item>
        <item>袁成杰</item>
        <item>戚薇</item>
        <item>齐大友</item>
        <item>齐天大圣</item>
        <item>品冠</item>
        <item>吴克群</item>
        <item>BOBO</item>
        <item>Jobs</item>
        <item>动力火车</item>
        <item>伍佰</item>
        <item>#蔡依林</item>
        <item>$797835344$</item>
        <item>Jack</item>
        <item>~夏先生</item>
    </string-array>

</resources>

打完收工~