Android 获取系统联系人并排序，不需要拼音Jar包

项目需要做到这个效果，是读取系统联系人及其邮箱地址，选中后进行邮件分享的功能。

在读取联系人时，QC提到并未排序，最开始说，数字、英文、中文（中文按笔画排序）我说，按正常人，都是拼音排序的吧？谁知道人家说，我们香港那边都是按笔画排序的(* ￣︿￣)，谈论到最后，说，数字、英文、中文（按拼音排序），起初答应了，后来觉得太烦，这个东西本身不是客户的需求，只是QC自以为是的想法，觉得置之不理，以系统为准，系统怎么排，就怎么排。

原本我获取系统联系人及其邮箱的代码：

/**
 * 读取联系人的信息
 * Gift
 */

public static List readContactsEmail(Context mContext) {
    List contactsBeans = new ArrayList<>();
    ContactsBean contactsBean;
    Cursor cursor = mContext.getContentResolver().query(ContactsContract.Contacts.CONTENT_URI,
            null, null, null, null);
    int contactIdIndex = 0;
    int nameIndex = 0;

    if (cursor.getCount() > 0) {
        contactIdIndex = cursor.getColumnIndex(ContactsContract.Contacts._ID);
        nameIndex = cursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME);
    }
    while (cursor.moveToNext()) {
        contactsBean = new ContactsBean();
        String contactId = cursor.getString(contactIdIndex);
        contactsBean.setName(cursor.getString(nameIndex));
        /*
         * 查找该联系人的email信息
         */
        Cursor emails = mContext.getContentResolver().query(ContactsContract.CommonDataKinds.Email.CONTENT_URI,
                null,
                ContactsContract.CommonDataKinds.Email.CONTACT_ID + "=" + contactId,
                null, null);
        int emailIndex = 0;
        if (emails.getCount() > 0) {
            emailIndex = emails.getColumnIndex(ContactsContract.CommonDataKinds.Email.DATA);
        }
        while (emails.moveToNext()) {
            contactsBean.setEmail(emails.getString(emailIndex));
        }
        if (!StringUtils.isBlank(contactsBean.getEmail())) {
            contactsBeans.add(contactsBean);
        }
    }

    return contactsBeans;
}

这里用到的 ContactsBean 的实体类的内容为：

String name = "";
String email = "";

http://blog.chinaunix.net/uid-23023613-id-3023387.html

通过这位博主的资料，我得知 ：

通讯录的数据库文件contacts2.db的raw_contacts表。用sqlitedbviewer工具打开后可以看到有这么一个字段：sort_key（sort_key_alt与之相似，只不过是英文环境下有个按given name还是first name排序的问题）。

正常状况下，我们新建一个联系人的话，如果是英文，则sort_key与display_name字段显示相同，如果输入姓名是中文，如“你好”，sort_key则会显示“ni 你 hao 好”，这样开发者既可以根据此字段按拼音排序，中英文混排，以及按拼音搜索联系人拉。

既然有这个字段，那就好办了。通过查看

ContactsContract.Contacts

的源码，发现：

/**
 * Sort key that takes into account locale-based traditions for sorting
 * names in address books.  The default
 * sort key is {@link #DISPLAY_NAME_PRIMARY}.  For Chinese names
 * the sort key is the name's Pinyin spelling, and for Japanese names
 * it is the Hiragana version of the phonetic name.
 */
public static final String SORT_KEY_PRIMARY = "sort_key";

解释也很明朗。于是我将上面获取的方法的代码改为：

/**
 * 读取联系人的信息
 * Gift
 */

public static List readContactsEmail(Context mContext) {
    List contactsBeans = new ArrayList<>();
    ContactsBean contactsBean;
    Cursor cursor = mContext.getContentResolver().query(ContactsContract.Contacts.CONTENT_URI,
            null, null, null, ContactsContract.Contacts.SORT_KEY_PRIMARY);
    int contactIdIndex = 0;
    int nameIndex = 0;
    int sort_key = 0;

    if (cursor.getCount() > 0) {
        contactIdIndex = cursor.getColumnIndex(ContactsContract.Contacts._ID);
        nameIndex = cursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME);
        sort_key = cursor.getColumnIndex(ContactsContract.Contacts.SORT_KEY_PRIMARY);
    }
    while (cursor.moveToNext()) {
        contactsBean = new ContactsBean();
        String contactId = cursor.getString(contactIdIndex);
        contactsBean.setName(cursor.getString(nameIndex));
        contactsBean.setSort_key(getSortKey(cursor.getString(sort_key)));
        /*
         * 查找该联系人的email信息
*/
        Cursor emails = mContext.getContentResolver().query(ContactsContract.CommonDataKinds.Email.CONTENT_URI,
                null,
                ContactsContract.CommonDataKinds.Email.CONTACT_ID + "=" + contactId,
                null, null);
        int emailIndex = 0;
        if (emails.getCount() > 0) {
            emailIndex = emails.getColumnIndex(ContactsContract.CommonDataKinds.Email.DATA);
        }
        while (emails.moveToNext()) {
            contactsBean.setEmail(emails.getString(emailIndex));
        }
        if (!StringUtils.isBlank(contactsBean.getEmail())) {
            contactsBeans.add(contactsBean);
        }
    }


    return contactsBeans;
}

附上getSortKey方法：

/**
 * 获取sort key的首个字符，并将其转换成大写，如果是英文字母就直接返回，否则返回#。
 * @param str_sortKey 数据库中读取出的sort key
 * @return 首字母、#
 * Gift
 */
private static String getSortKey(String str_sortKey) {
    String sort_key = str_sortKey.substring(0, 1).toUpperCase();
    if (sort_key.matches("[A-Z]")) {
        return sort_key;
    }
    return "#";
}

这样返回回来，就是已经按sortKey排好序的列表了。重点在于

Cursor cursor = mContext.getContentResolver().query(ContactsContract.Contacts.CONTENT_URI,
            null, null, null, ContactsContract.Contacts.SORT_KEY_PRIMARY);

最后一个传值。

/**
 * Query the given URI, returning a {@link Cursor} over the result set.
 * 

 * For best performance, the caller should follow these guidelines:
 * 

 * 
Provide an explicit projection, to prevent
 * reading data from storage that aren't going to be used.

 * 
Use question mark parameter markers such as 'phone=?' instead of
 * explicit values in the {@code selection} parameter, so that queries
 * that differ only by those values will be recognized as the same
 * for caching purposes.

 * 

 * 

 *
 * @param uri The URI, using the content:// scheme, for the content to
 *         retrieve.
 * @param projection A list of which columns to return. Passing null will
 *         return all columns, which is inefficient.
 * @param selection A filter declaring which rows to return, formatted as an
 *         SQL WHERE clause (excluding the WHERE itself). Passing null will
 *         return all rows for the given URI.
 * @param selectionArgs You may include ?s in selection, which will be
 *         replaced by the values from selectionArgs, in the order that they
 *         appear in the selection. The values will be bound as Strings.
 * @param sortOrder How to order the rows, formatted as an SQL ORDER BY
 *         clause (excluding the ORDER BY itself). Passing null will use the
 *         default sort order, which may be unordered.
 * @return A Cursor object, which is positioned before the first entry, or null
 * @see Cursor
 */
public final Cursor query(Uri uri, String[] projection,
        String selection, String[] selectionArgs, String sortOrder) {
    return query(uri, projection, selection, selectionArgs, sortOrder, null);
}

传入sort_key，按sort_key排序，传null可能是无序的，但我起初传null的时候，是按我添加通讯录时的顺序返回的，应该是按添加时间排序。

但不论如何，我们所要的效果已经达到了。