读取系统的联系人

1.activity_main.xml

   

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    android:id="@+id/activity_main"
    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"
    tools:context="com.sh.contactstest.MainActivity">

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

     </ListView>

</LinearLayout>

2.MainActivity.java

public class MainActivity extends AppCompatActivity {
     ArrayAdapter<String>  adapter;
     List contactsList = new ArrayList<String>();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ListView contactsView = (ListView)findViewById(R.id.contacts_view);
        adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,contactsList);
        contactsView.setAdapter(adapter);
        if (ContextCompat.checkSelfPermission(this, android.Manifest.permission.READ_CONTACTS)!=
                PackageManager.PERMISSION_GRANTED)
        {
            ActivityCompat.requestPermissions(this,new String[]{android.Manifest.permission.READ_CONTACTS},1);
        } else{
            readContacts();
        }
    }

    private void readContacts()
    {
        Cursor cursor =null;
        try{
            //查询联系人的数据
            cursor = getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI,null,null,null,null);
            if (cursor!=null){
                while (cursor.moveToNext())
                {
                    //获取联系人的姓名
                    String displayName = cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME));
                    //获取联系人的手机 号
                    String number =cursor.getString((cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER)));
                    contactsList.add(displayName + "\n" + number);
                }
                adapter.notifyDataSetChanged();
            }
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }finally {
            if (cursor != null) {
                 cursor.close();
            }
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {

        switch ( requestCode){
            case 1:
                if (grantResults.length >0 && grantResults[0] == PackageManager.PERMISSION_GRANTED){
                    readContacts();
                }else {
                    Toast.makeText(this, "you denied the permission", Toast.LENGTH_SHORT).show();
                }
                break;
            default:

        }
    }
}

3.AndroidManifest.xml

<manifest package="com.sh.contactstest"
          xmlns:android="http://schemas.android.com/apk/res/android">
      <uses-permission android:name="android.permission.READ_CONTACTS"/>
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>

                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>
    </application>

</manifest>