微信中聯絡人，訂閱號都是按拼音排序的，在按拼音排序的基礎上才能索引，雖然微信從資料庫取出的就是排好序的，我們今天就對List裡的無序資料進行排序。

首先定義一個聯絡人類Contact：

/**
 * Created by dhl on 2017/5/10.
 */

public class Contact {
    private String name ;
    private String py ;

    public Contact(String name ,String py)
    {
        this.name = name ;
        this.py = py ;
    }
    public String getName() {
        return name;
    }

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

    public String getPy() {
        return py;
    }

    public void setPy(String py) {
        this.py = py;
    }
}
 

這裡先逆序造一些資料：

  Contact contact = null;
        //倒敘abcd測試
        for (char i = 'z'; i >='a' ; i--) {
             contact = new Contact("張三"+i,i+"");
            contactList.add(contact);
        }

 /**
     * 實現Comparator介面
     */
    class ContactComparator implements Comparator<Contact>
    {

        @Override
        public int compare(Contact o1, Contact o2) {
            return o1.getPy().compareTo(o2.getPy());
        }
    }
 

  Collections.sort(contactList,new ContactComparator());

下面貼出全部程式碼：

main.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.dhl.objectsort.MainActivity">



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

</LinearLayout>
 

public class MainActivity extends AppCompatActivity {

    private List<Contact> contactList ;
    private ListView listView ;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        listView = (ListView)findViewById(R.id.list_contact);
        initData();
        listView.setAdapter(new CommonAdapter<Contact>(this,R.layout.contact_item,contactList) {
            @Override
            protected void convert(ViewHolder viewHolder, Contact item, int position) {
                viewHolder.setText(R.id.contact_text,item.getName()+"\n"+item.getPy());
            }
        });
    }
    private void initData()
    {
        contactList = new ArrayList<>();
        Contact contact = null;
        //倒敘abcd測試
        for (char i = 'z'; i >='a' ; i--) {
             contact = new Contact("張三"+i,i+"");
            contactList.add(contact);
        }
        Collections.sort(contactList,new ContactComparator());

    }

    /**
     * 實現Comparator介面
     */
    class ContactComparator implements Comparator<Contact>
    {

        @Override
        public int compare(Contact o1, Contact o2) {
            return o1.getPy().compareTo(o2.getPy());
        }
    }

}

compile 'com.zhy:base-adapter:3.0.3'

這裡是逆序：

按拼音排序順利完成。