Android实现字母索引查找地名、联系人（一）

在我们的智能手机使用中，经常会见到如联系人列表、城市名列表，需要寻找时，常见有两种方式：1、搜索，2、字母索引。今天我就分享下自己学习使用字母索引功能。Demo效果如下：



字母索引大体上实现原理为：

1）创建一个ListView(或者扩展ListV），展示联系人或城市、省份名；

2）在屏幕右边实现一个ListView，显示用作索引的字母；

3）当用户按下索引字母时，查找联系人或城市列表，找出第一个与之匹配的项，使listView跳转到该项。



代码实现如下：

1）显示城市名称

listView = (ListView) findViewById(R.id.listView);
        adapter = new ArrayAdapter(context, android.R.layout.simple_list_item_1, android.R.id.text1,
                Cities.mCitiesStrings);
        listView.setAdapter(adapter);
        listView.setOnItemClickListener(itemClickListener);

2）显示索引字母，这一段是动态添加的列表内容，包含点击某个字母，城市列表跳转到索引字母开始的城市

LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
                ViewGroup.LayoutParams.WRAP_CONTENT);
        for(final char letter:Letters){
            TextView tv = new TextView(context);
            tv.setText(String.valueOf(letter));
            tv.setGravity(Gravity.CENTER);
            tv.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    String index = ((TextView) v).getText().toString();
                    Log.d(TAG, "onClick.letter = " + index);
                    listView.setSelection(getStartIndex(index));
                }
            });
            layout.addView(tv);
        }

3）根据字母查找索引字母开始的城市，因为保存的城市名称是汉字，所以此次需要进行转换，把汉字名称转换为拼音，使用了pinyin4j开源库，城市名字在我另一篇博客里有分享，几乎包含了中国所有的城市名

private int getStartIndex(String letter){
        int returnInt = 0;
        char index = 0;
        for(int i=0;i<Letters.length;i++){
            if(letter.equals(String.valueOf(Letters[i]))){
                index = Letters[i];
                break;
            }
        }
        for(int j = 0; j < Cities.mCitiesStrings.length; j++){
            String cityName = getPinYin(Cities.mCitiesStrings[j]);
            Log.d(TAG, "getStartIndex.cityName = " + cityName);
            if((cityName.toCharArray())[0] == index) {
                returnInt = j;
                break;
            }
        }

        return returnInt;
    }

4）调用pinyin4j开源库，将城市名称转换成拼音

private String getPinYin(String inputString){
        StringBuffer output = new StringBuffer("");

        HanyuPinyinOutputFormat format = new HanyuPinyinOutputFormat();
        format.setCaseType(HanyuPinyinCaseType.UPPERCASE);
        format.setToneType(HanyuPinyinToneType.WITHOUT_TONE);
        format.setVCharType(HanyuPinyinVCharType.WITH_V);

        char[] input = inputString.trim().toCharArray();

        try {
            for(int i = 0; i < input.length; i++){
                if (Character.toString(input[i]).matches("[\u4E00-\u9FA5]+")) {
                    String[] temp = new String[0];
                    temp = PinyinHelper.toHanyuPinyinStringArray(input[i], format);
                    output.append(temp[0]);
                    output.append(" ");
                } else
                    output.append(Character.toString(input[i]));
            }
        } catch (BadHanyuPinyinOutputFormatCombination badHanyuPinyinOutputFormatCombination) {
            badHanyuPinyinOutputFormatCombination.printStackTrace();
        }

        return  output.toString();
    }

布局文件如下（部分可忽略）：

<LinearLayout 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"
    android:orientation="vertical"
    android:background="@color/light"
    tools:context="com.huiyu.firstrankgas.ui.CityActivity">

    <include
        layout="@layout/topbar_view"/>

    <!-- 搜索栏-->
    <LinearLayout
        android:layout_marginTop="10dp"
        android:layout_marginBottom="10dp"
        android:layout_marginLeft="15dp"
        android:layout_marginRight="15dp"
        android:padding="5dp"
        android:background="@drawable/search_edit_bg"
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="40dp">

        <ImageView
            android:src="@drawable/search_icon"
            android:background="@color/light"
            android:layout_gravity="center_vertical"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />

        <EditText
            android:layout_gravity="center"
            android:background="@null"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:hint="@string/search_hint"
            android:textSize="@dimen/text_size_middle_18"/>
    </LinearLayout>

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <LinearLayout
            android:orientation="vertical"
            android:layout_width="match_parent"
            android:layout_height="match_parent">

            <LinearLayout
                android:background="@color/white"
                android:layout_width="match_parent"
                android:layout_height="40dp">
                <TextView
                    android:id="@+id/city"
                    style="@style/text_style2"
                    android:text="北京"
                    android:layout_gravity="center_vertical"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content" />
            </LinearLayout>

            <View
                android:layout_width="match_parent"
                android:layout_height="30dp"/>

            <ListView
                android:id="@+id/listView"
                android:background="@color/white"
                android:dividerHeight="1dp"
                android:layout_width="match_parent"
                android:layout_height="match_parent"/>
        </LinearLayout>

        <LinearLayout
            android:id="@+id/letter_index"
            android:layout_gravity="right"
            android:orientation="vertical"
            android:layout_width="30dp"
            android:layout_height="match_parent">
        </LinearLayout>

    </FrameLayout>

</LinearLayout>

实现代码如下：

public class CityActivity extends Activity {

    private static final String TAG = "CityActivity";
    private char[] Letters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".toCharArray();
    private Context context;
    private ListView listView;
    private ArrayAdapter adapter;
    private LinearLayout layout;
    private TextView textView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_city);

        initView();
    }

    private void initView(){
        context = CityActivity.this;

        textView = (TextView) findViewById(R.id.city);
       listView = (ListView) findViewById(R.id.listView);
        adapter = new ArrayAdapter(context, android.R.layout.simple_list_item_1, android.R.id.text1,
                Cities.mCitiesStrings);
        listView.setAdapter(adapter);
        listView.setOnItemClickListener(itemClickListener);

        layout = (LinearLayout) findViewById(R.id.letter_index);
      LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
                ViewGroup.LayoutParams.WRAP_CONTENT);
        for(final char letter:Letters){
            TextView tv = new TextView(context);
            tv.setText(String.valueOf(letter));
            tv.setGravity(Gravity.CENTER);
            tv.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    String index = ((TextView) v).getText().toString();
                    Log.d(TAG, "onClick.letter = " + index);
                    listView.setSelection(getStartIndex(index));
                }
            });
            layout.addView(tv);
        }
    }

private int getStartIndex(String letter){
        int returnInt = 0;
        char index = 0;
        for(int i=0;i<Letters.length;i++){
            if(letter.equals(String.valueOf(Letters[i]))){
                index = Letters[i];
                break;
            }
        }
        for(int j = 0; j < Cities.mCitiesStrings.length; j++){
            String cityName = getPinYin(Cities.mCitiesStrings[j]);
            Log.d(TAG, "getStartIndex.cityName = " + cityName);
            if((cityName.toCharArray())[0] == index) {
                returnInt = j;
                break;
            }
        }

        return returnInt;
    }

    AdapterView.OnItemClickListener itemClickListener =  new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            Log.d(TAG, "onItemClick() called with " + "parent = [" + parent + "], view = [" + view + "], position = [" + position + "], id = [" + id + "]");
            String choice = Cities.mCitiesStrings[position];
            Log.d(TAG, "onItemClick.choice = " + choice);
            textView.setText(choice);
        }
    };

private String getPinYin(String inputString){
        StringBuffer output = new StringBuffer("");

        HanyuPinyinOutputFormat format = new HanyuPinyinOutputFormat();
        format.setCaseType(HanyuPinyinCaseType.UPPERCASE);
        format.setToneType(HanyuPinyinToneType.WITHOUT_TONE);
        format.setVCharType(HanyuPinyinVCharType.WITH_V);

        char[] input = inputString.trim().toCharArray();

        try {
            for(int i = 0; i < input.length; i++){
                if (Character.toString(input[i]).matches("[\u4E00-\u9FA5]+")) {
                    String[] temp = new String[0];
                    temp = PinyinHelper.toHanyuPinyinStringArray(input[i], format);
                    output.append(temp[0]);
                    output.append(" ");
                } else
                    output.append(Character.toString(input[i]));
            }
        } catch (BadHanyuPinyinOutputFormatCombination badHanyuPinyinOutputFormatCombination) {
            badHanyuPinyinOutputFormatCombination.printStackTrace();
        }

        return  output.toString();
    }

}

参考文章：

http://www.oschina.net/question/96894_24933