仿通讯录右边的字母搜索

1、添加依赖

把中文转成拼音才能按首字母进行排序

implementation 'com.belerweb:pinyin4j:2.5.1'

2、三个工具类

PinYinUtils

public class PinYinUtils {
    /**
     * 返回首字母，大写
     *
     * @param str
     * @return
     */
    public static String getFirstLetter(String str) {
        if (TextUtils.isEmpty(str)) {
            return "";
        } // 得到一个字符串的拼音的大写
        String pinyinStr = getPinyin(str).toUpperCase();
        // 取拼音字符串的第一个字母
//        String first = pinyinStr.substring(0, 1).toLowerCase();
//        if (first.matches("[a-z]")) {
//
//        } else {
//
//        }
        char firstCahr = pinyinStr.charAt(0);
        // 不是A-Z字母
        if (firstCahr > 90 || firstCahr < 65) {
            return "#";
        } else { // 代表是A-Z
            return String.valueOf(firstCahr);
        }
    }

    /**
     * 得到一个字符串的拼音读音
     *
     * @param chineseStr
     * @return
     */
    public static String getPinyin(String chineseStr) {
        StringBuffer sb = new StringBuffer();
        // 将汉字拆分成一个个的char
        char[] chars = chineseStr.toCharArray();
        // 遍历汉字的每一个char
        for (int i = 0; i < chars.length; i++) {
            try { // 汉字的所有读音放在一个pinyins数组
                String[] pinyins = PinyinHelper.toHanyuPinyinStringArray(chars[i], getDefaultFormat());
                if (pinyins == null) {
                    sb.append(chars[i]);
                } else {
                    sb.append(pinyins[0]);
                }
            } catch (BadHanyuPinyinOutputFormatCombination badHanyuPinyinOutputFormatCombination) {
                badHanyuPinyinOutputFormatCombination.printStackTrace();
            }
        }
        return sb.toString();
    }

    /**
     * 设置默认的输出格式
     *
     * @return
     */
    public static HanyuPinyinOutputFormat getDefaultFormat() {
        HanyuPinyinOutputFormat outputFormat = new HanyuPinyinOutputFormat();
        // 去除声调
        outputFormat.setToneType(HanyuPinyinToneType.WITHOUT_TONE);
        // 小写
        outputFormat.setCaseType(HanyuPinyinCaseType.LOWERCASE);
        // 包含Unicode特殊字符
        outputFormat.setVCharType(HanyuPinyinVCharType.WITH_U_UNICODE);
        return outputFormat;
    }
}

SystemUtil

public class SystemUtil {

    /**
     * 检查WIFI是否连接
     */
    public static boolean isWifiConnected() {
        ConnectivityManager connectivityManager = (ConnectivityManager) BaseApp.getInstance().getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo wifiInfo = connectivityManager
                .getNetworkInfo(ConnectivityManager.TYPE_WIFI);
        return wifiInfo != null;
    }
    /**
     * 检查手机网络(4G/3G/2G)是否连接
     */
    public static boolean isMobileNetworkConnected() {
        ConnectivityManager connectivityManager = (ConnectivityManager) BaseApp.getInstance().getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo mobileNetworkInfo = connectivityManager
                .getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
        return mobileNetworkInfo != null;
    }
    /**
     * 检查是否有可用网络
     */
    public static boolean isNetworkConnected() {
        ConnectivityManager connectivityManager = (ConnectivityManager) BaseApp.getInstance().getSystemService(Context.CONNECTIVITY_SERVICE);
        return connectivityManager.getActiveNetworkInfo() != null;
    }

    /**
     * 保存文字到剪贴板
     * @param context
     * @param text
     */
    public static void copyToClipBoard(Context context, String text) {
        ClipData clipData = ClipData.newPlainText("url", text);
        ClipboardManager manager = (ClipboardManager) context.getSystemService(Context.CLIPBOARD_SERVICE);
        manager.setPrimaryClip(clipData);
        Toast.makeText(context,"已复制到剪贴板",Toast.LENGTH_SHORT).show();
    }

    /**
     * 保存图片到本地
     * @param context
     * @param url
     * @param bitmap
     */
    public static Uri saveBitmapToFile(Context context, String url, Bitmap bitmap,
                                       View container, boolean isShare){
        String fileName = url.substring(url.lastIndexOf("/"),url.lastIndexOf(".")) + ".png";
        File fileDir = new File(Constants.PATH_SDCARD);
        if (!fileDir.exists()){
            fileDir.mkdirs();
        }
        File imageFile = new File(fileDir,fileName);
        Uri uri = Uri.fromFile(imageFile);
        if (isShare && imageFile.exists()) {
            if (Build.VERSION.SDK_INT >= 24) {
                uri = FileProvider.getUriForFile(context.getApplicationContext(),
                        Constants.FILE_PROVIDER_AUTHORITY, imageFile);
            }
            return uri;
        }
        try {
            FileOutputStream fos = new FileOutputStream(imageFile);
            boolean isCompress = bitmap.compress(Bitmap.CompressFormat.PNG, 90, fos);
            if (isCompress) {
                ToastUtil.showShort("保存妹纸成功n(*≧▽≦*)n");
            } else {
                ToastUtil.showShort("保存妹纸失败ヽ(≧Д≦)ノ");
            }
            fos.flush();
            fos.close();
        } catch (IOException e) {
            e.printStackTrace();
            ToastUtil.showShort("保存妹纸失败ヽ(≧Д≦)ノ");
        }
        try {
            MediaStore.Images.Media.insertImage(context.getContentResolver(), imageFile.getAbsolutePath(), fileName, null);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        context.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE,uri));
        if (Build.VERSION.SDK_INT >= 24) {
            uri = FileProvider.getUriForFile(context.getApplicationContext(),
                    Constants.FILE_PROVIDER_AUTHORITY, imageFile);
        }
        return uri;
    }

    /**
     * 根据手机的分辨率从 dp 的单位 转成为 px(像素)
     */
    public static int dp2px(Context context, float dpValue) {
        final float scale = context.getResources().getDisplayMetrics().density;
        return (int) (dpValue * scale + 0.5f);
    }

    public static int dp2px(float dpValue) {
        final float scale = BaseApp.getInstance().getResources().getDisplayMetrics().density;
        return (int) (dpValue * scale + 0.5f);
    }

    /**
     * 根据手机的分辨率从 px(像素) 的单位 转成为 dp
     */
    public static int px2dp(Context context, float pxValue) {
        final float scale = context.getResources().getDisplayMetrics().density;
        return (int) (pxValue / scale + 0.5f);
    }

    public static int px2dp(float pxValue) {
        final float scale = BaseApp.getInstance().getResources().getDisplayMetrics().density;
        return (int) (pxValue / scale + 0.5f);
    }

    /**
     * 获取进程号对应的进程名
     *
     * @param pid 进程号
     * @return 进程名
     */
    public static String getProcessName(int pid) {
        BufferedReader reader = null;
        try {
            reader = new BufferedReader(new FileReader("/proc/" + pid + "/cmdline"));
            String processName = reader.readLine();
            if (!TextUtils.isEmpty(processName)) {
                processName = processName.trim();
            }
            return processName;
        } catch (Throwable throwable) {
            throwable.printStackTrace();
        } finally {
            try {
                if (reader != null) {
                    reader.close();
                }
            } catch (IOException exception) {
                exception.printStackTrace();
            }
        }
        return null;
    }
}

ToastUtil

public class ToastUtil {
    public static void showShort(String msg){
        //避免内存泄漏的一个方法,用到上下文的地方,能用application的就application
        Toast.makeText(BaseApp.getInstance(),msg,Toast.LENGTH_SHORT).show();
    }
    public static void showLong(String msg){
        //避免内存泄漏的一个方法,用到上下文的地方,能用application的就application
        Toast.makeText(BaseApp.getInstance(),msg,Toast.LENGTH_LONG).show();
    }
}

3、Constants（常量接口）

public interface Constants {
    boolean isDebug = true;


    String PATH_SDCARD = Environment.getExternalStorageDirectory().getAbsolutePath() +
            File.separator + "codeest" + File.separator + "GeekNews";

    String FILE_PROVIDER_AUTHORITY="com.baidu.geek.fileprovider";

    //网络缓存的地址
    String PATH_DATA = BaseApp.getInstance().getCacheDir().getAbsolutePath() +
            File.separator + "data";
}

4、BaseApp

别忘了在清单文件中配置

public class BaseApp extends Application {
    private static BaseApp sBaseApp;
    //默认不是夜间模式
    public static int mMode = AppCompatDelegate.MODE_NIGHT_NO;
    public static int mWidthPixels;
    public static int mHeightPixels;

    @Override
    public void onCreate() {
        super.onCreate();
        sBaseApp = this;
        getScreenWH();


    }

    //计算屏幕宽高
    private void getScreenWH() {
        WindowManager manager = (WindowManager) getSystemService(WINDOW_SERVICE);
        Display defaultDisplay = manager.getDefaultDisplay();
        DisplayMetrics metrics = new DisplayMetrics();
        defaultDisplay.getMetrics(metrics);
        mWidthPixels = metrics.widthPixels;
        mHeightPixels = metrics.heightPixels;
    }

    public static BaseApp getInstance(){
        return sBaseApp;
    }

    public static Resources getRes() {
        return sBaseApp.getResources();
    }
}

5、MyLetterView（自定义view）

public class MyLetterView extends View {
    public static String[] letters = { "*" ,"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 Paint paint = new Paint();
    /**
     * 用于标记哪个位置被选中
     */
    private int choose = -1;
    //该TextView是左边显示的对话框
    private TextView mTextDialog;

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

    private OnTouchingLetterChangedListener listener;

    public void setOnTouchingLetterChangedListener(OnTouchingLetterChangedListener listener) {
        this.listener = listener;
    }

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

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

    public MyLetterView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        // 获取该自定义View的宽度和高度
        int width = getWidth();
        int height = getHeight();

        // 单个字母的高度
        int singleHeight = height / letters.length;

        for (int i = 0; i < letters.length; i++) {
            paint.setColor(getResources().getColor(
                    R.color.c_fa6a13));
            paint.setTypeface(Typeface.DEFAULT_BOLD);
            paint.setAntiAlias(true);
            paint.setTextSize(SystemUtil.dp2px(12));

            // 如果选中的话,改变样式和颜色
            if (i == choose) {
                paint.setColor(Color.parseColor("#3399ff"));
                paint.setFakeBoldText(true);
            }

            // 首先确定每个字母的横坐标的位置，横坐标：该自定义View的一半 -（减去） 单个字母宽度的一半
            float xPos = width / 2 - paint.measureText(letters[i]) / 2;
            float yPos = singleHeight * (i + 1);

            canvas.drawText(letters[i], xPos, yPos, paint);

            // 重置画笔
            paint.reset();
        }
    }

    @SuppressWarnings("deprecation")
    @Override
    public boolean dispatchTouchEvent(MotionEvent event) {

        int action = event.getAction();
        float y = event.getY();

        int oldChoose = choose;
        // 根据y坐标确定当前哪个字母被选中
        int pos = (int) (y / getHeight() * letters.length);

        switch (action) {
            case MotionEvent.ACTION_UP:
                // 当手指抬起时,设置View的背景为白色
                setBackgroundDrawable(new ColorDrawable(0x00000000));
                // 重置为初始状态
                choose = -1;
                // 让View重绘
                invalidate();

                // 将对话框设置为不可见
                if (mTextDialog != null) {
                    mTextDialog.setVisibility(View.INVISIBLE);
                }

                break;
            default:
                // 设置右边字母View的背景色
//                setBackgroundResource(R.drawable.);
                if (pos != oldChoose) {
                    // 如果之前选中的和当前的不一样，需要重绘
                    if (pos >= 0 && pos < letters.length) {
                        if(listener != null) {
                            //当前字母被选中，需要让ListView去更新显示的位置
                            listener.onTouchingLetterChanged(letters[pos]);
                        }
                        //在左边显示选中的字母，该字母放在TextView上，相当于一个dialog
                        if (mTextDialog != null) {
                            mTextDialog.setText(letters[pos]); //让对话框显示响应的字母
                            mTextDialog.setVisibility(View.VISIBLE);
                        }
                        choose = pos;  //当前位置为选中位置
                    }
                }
                break;
        }

        return true;
    }

    /**
     * 该回调接口用于通知ListView更新状态
     */
    public interface OnTouchingLetterChangedListener {
        public void onTouchingLetterChanged(String s);
    }
}

6、User（实体类）

public class User implements Comparable<User> {
    private String name; // 姓名
    private String pinyin; // 姓名对应的拼音
    private String firstLetter; // 拼音的首字母

    public User() {
    }

    public User(String name) {
        this.name = name;
        pinyin = PinYinUtils.getPinyin(name); // 根据姓名获取拼音
        firstLetter = pinyin.substring(0, 1).toUpperCase(); // 获取拼音首字母并转成大写
        if (!firstLetter.matches("[A-Z]")) { // 如果不在A-Z中则默认为“#”
            firstLetter = "#";
        }
    }

    public String getName() {
        return name;
    }

    public String getPinyin() {
        return pinyin;
    }

    public String getFirstLetter() {
        return firstLetter;
    }

    @Override
    public int compareTo(User another) {
        if (firstLetter.equals("#") && !another.getFirstLetter().equals("#")) {
            return 1;
        } else if (!firstLetter.equals("#") && another.getFirstLetter().equals("#")) {
            return -1;
        } else {
            return pinyin.compareToIgnoreCase(another.getPinyin());
        }
    }
}

7、MainActivity

xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <ListView
        android:id="@+id/list_friends"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    </ListView>

    <TextView
        android:id="@+id/dialog"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:text="212"
        android:visibility="gone"/>

    <com.example.pinyin.MyLetterView
        android:id="@+id/right_letter"
        android:layout_width="9dp"
        android:layout_height="match_parent"
        android:layout_alignParentRight="true"
        android:layout_marginRight="10dp"/>

</RelativeLayout>

MainActivity

public class MainActivity extends AppCompatActivity {

    private ArrayList<User> list;
    private ListView list_friends;
    private MyLetterView right_letter;
    private TextView dialog;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initData();
        initView();
    }

    private void initData() {
        list = new ArrayList<>();
        list.add(new User("亳州")); // 亳[bó]属于不常见的二级汉字
        list.add(new User("蚌埠"));
        list.add(new User("合肥"));
        list.add(new User("北京"));
        list.add(new User("天津"));
        list.add(new User("苏州"));
        list.add(new User("宿州"));
        list.add(new User("淮北"));
        list.add(new User("淮南"));
        list.add(new User("黄山"));
        list.add(new User("阜阳"));
        list.add(new User("滁州"));
        list.add(new User("马鞍山"));
        list.add(new User("芜湖"));
        list.add(new User("铜陵"));
        list.add(new User("安庆"));
        list.add(new User("六安"));
        list.add(new User("池州"));
        list.add(new User("巢湖"));
        list.add(new User("宣城"));
        list.add(new User("福州"));
        list.add(new User("南平"));
        list.add(new User("界首"));
        list.add(new User("明光"));
        list.add(new User("天长"));
        list.add(new User("桐城"));
        list.add(new User("宁国"));
        list.add(new User("厦门"));
        list.add(new User("三明"));
        list.add(new User("莆田"));
        list.add(new User("泉州"));
        list.add(new User("怀远"));
        list.add(new User("漳州"));
        list.add(new User("龙岩"));
        list.add(new User("兰州"));
        list.add(new User("贵阳"));
        list.add(new User("石家庄"));
        list.add(new User("张三"));
        list.add(new User("李四"));
        list.add(new User("哈尔滨"));
        list.add(new User("郑州"));
        list.add(new User("武汉"));
        list.add(new User("长沙"));
        list.add(new User("长春"));
        list.add(new User("南京"));
        list.add(new User("南昌"));
        list.add(new User("沈阳"));
        list.add(new User("大连"));

        Collections.sort(list); // 对list进行排序，需要让User实现Comparable接口重写compareTo方法

    }

    private void initView() {
        list_friends = (ListView) findViewById(R.id.list_friends);
        right_letter = (MyLetterView) findViewById(R.id.right_letter);
        dialog = (TextView) findViewById(R.id.dialog);
        right_letter.setTextDialog(dialog);
        final FriendsAdapter adapter = new FriendsAdapter(list, this);

        right_letter.setOnTouchingLetterChangedListener(new MyLetterView.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) {
                    list_friends.setSelection(position);
                }
            }
        });

        list_friends.setAdapter(adapter);

    }
}

8、FriendsAdapter（适配器）

public class FriendsAdapter extends BaseAdapter {

    ArrayList<User> list;
    Context context;

    public FriendsAdapter(ArrayList<User> list, Context context) {
        this.list = list;
        this.context = 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 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder viewHolder = null;
        if(convertView == null) {
            convertView = LayoutInflater.from(context).inflate(R.layout.item_user_friend, null);
            viewHolder = new ViewHolder();
            viewHolder.name = (TextView) convertView.findViewById(R.id.tv_friend_name);
            viewHolder.alpha = (TextView) convertView.findViewById(R.id.alpha);
            convertView.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) convertView.getTag();
        }

        User friend = list.get(position);
        viewHolder.name.setText(friend.getName());

        // 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.alpha.setVisibility(View.VISIBLE);
            viewHolder.alpha.setText(friend.getFirstLetter());
        } else {
            viewHolder.alpha.setVisibility(View.GONE);
        }
        return convertView;
    }

    static class ViewHolder {
        TextView name;
        TextView alpha;;
    }
    //判断当前位置是否是该位置对应的字母第一次出现
    public int getPositionForSection(int section) {
        for (int i = 0; i < getCount(); i++) {
            String sortStr = list.get(i).getFirstLetter();
            char firstChar = sortStr.toUpperCase().charAt(0);
            if (section == firstChar) {
                return i;
            }
        }
        return -1;
    }

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