/*
 * 开启服务
 */
public void start(View view) {
  Intent intent = new Intent(this, MyService.class);
  startService(intent);
}
/*
 * 结束服务
 */
public void stop(View view) {
  Intent intent = new Intent(this, MyService.class);
  stopService(intent);
}

public class MyService extends Service {
  /*
   * 绑定时调用
   */
  public IBinder onBind(Intent intent) {
    return null;
  }
  /*
   * 开启服务时调用
   */
  public void onCreate() {
    super.onCreate();
    System.out.println("onCreate");
  }
  /*
   * 结束服务时调用
   */
  public void onDestroy() {
    super.onDestroy();
    System.out.println("onDestroy");
  }
}

@Override
public void onCreate() {
  //拿到电话服务
  TelephonyManager manager = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
  //电话的状态监听器
  manager.listen(new MyListener(), PhoneStateListener.LISTEN_CALL_STATE);
}
private final class MyListener extends PhoneStateListener {
  private String num;
  private MediaRecorder recorder;  //录音
  private File file;
  public void onCallStateChanged(int state, String incomingNumber) {
    switch (state) {
      //响铃状态
      case TelephonyManager.CALL_STATE_RINGING:
        //保存电话号
        num = incomingNumber;
        break;
      //接通电话状态
      case TelephonyManager.CALL_STATE_OFFHOOK:
        try {
          //设置文件保存位置
          file = new File(Environment.getExternalStorageDirectory(), num + "_" + System.currentTimeMillis() + ".3gp");
          //创建录音器
          recorder = new MediaRecorder();
          //设置音频的来源(麦克风)
          recorder.setAudioSource(AudioSource.MIC);
          //采取3gp格式保存
          recorder.setOutputFormat(OutputFormat.THREE_GPP);
          //设置编码器
          recorder.setAudioEncoder(AudioEncoder.AMR_NB);
          //输出文件路径
          recorder.setOutputFile(file.getAbsolutePath());
          //准备
          recorder.prepare();
          //录音
          recorder.start();
        } catch (Exception e) {
          e.printStackTrace();
        }
        break;
      //电话空闲状态
      case TelephonyManager.CALL_STATE_IDLE:
        //电话挂断后停止录音
        if (recorder != null) {
          recorder.stop();
          recorder.release();
        }
        break;
    }
  }
}

<!-- 读电话的状态权限 -->
<uses-permission android:name="android.permission.READ_PHONE_STATE" />
<!-- 录音权限 -->
<uses-permission android:name="android.permission.RECORD_AUDIO" />
<!-- sdCard读的权限 -->
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />
<!-- sdCard写的权限 -->
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<!-- 打开网络权限 -->
<uses-permission android:name="android.permission.INTERNET" />

public class MainActivity extends Activity {
  private QueryService qs;
  private EditText editText;
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    editText = (EditText) findViewById(R.id.id);
    // 绑定服务, 传入ServiceConnection用来接收IBinder
    bindService(new Intent(this, PersonService.class), new MyConn(), BIND_AUTO_CREATE);
  }
  /*
   * 自定义的ServiceConnection用来接收IBinder
   */
  private final class MyConn implements ServiceConnection {
    public void onServiceConnected(ComponentName name, IBinder service) {
      qs = (QueryService) service;
    }
    public void onServiceDisconnected(ComponentName name) {
    }
  }
  /*
   * 根据Id获取联系人
   */
  public void queryName(View view) {
    String id = editText.getText().toString();
    String name = qs.query(Integer.parseInt(id));
    Toast.makeText(this, name, 0).show();
  }
}

public class PersonService extends Service {
  private String[] data = { "zxx", "lhm", "flx" };
  /*
   * 当绑定时调用此方法, 返回一个IBinder, 用来调用当前服务中的方法
   */
  public IBinder onBind(Intent intent) {
    return new MyBinder();
  }
  /*
   * 查询方法
   */
  public String query(int id) {
    return data[id];
  }
  /*
   * 自定义IBinder, 实现QueryService业务接口, 提供给调用者访问当前服务的方法
   */
  private final class MyBinder extends Binder implements QueryService {
    public String query(int id) {
      return PersonService.this.query(id);
    }
  }
}