2017.12.4 Android开发之ListView组件

<?xml version="1.0" encoding="utf-8"?>
<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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:orientation="vertical"
    tools:context="com.example.chuny.ch10listview.MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!" />
    <ListView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/listview"></ListView>
</LinearLayout>

    private List<String> getContactName(){
        List<String> contacts=new ArrayList<>();                  //List<String>指定List的类型只能是String
          //定义一个内容解析器，就是凡是读到手机系统资源的，都需要一个内容解析器
        ContentResolver cr=getContentResolver();
        //获取手机通信录的地址
        Cursor cursor=cr.query(ContactsContract.Contacts.CONTENT_URI,null,null,null,null);        //定义一个游标

        //循环读取通讯录里边的联系人
        if(cursor.moveToFirst()){
            do{
                String name=cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));        //游标类型转化为数据类型
                //读取手机通信录中的联系人姓名
                contacts.add(name);
            }while(cursor.moveToNext());
        }
        cursor.close();     //关闭游标，游标类似指针，读取数据库时
        return contacts;
    }

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        listView=(ListView)findViewById(R.id.listview);
       // ArrayAdapter<String> adapter=new ArrayAdapter<String>(MainActivity.this,R.layout.support_simple_spinner_dropdown_item,dataSource);
        //listView.setAdapter(adapter);
        ArrayAdapter<String> adapter=new ArrayAdapter<String>(MainActivity.this,R.layout.support_simple_spinner_dropdown_item,getContactName());
        listView.setAdapter(adapter);
    }