一、Model层

接口：

public interface IDataManager {
    String getMyLocation();
}

实现：

public class DataManager implements IDataManager {
    @Override
    public String getMyLocation() {
        return "北京";
    }
}

二、View层

布局文件：

//activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <TextView
        android:id="@+id/main_tv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:textSize="30sp"
        android:text="My Location" />
    <Button
        android:id="@+id/main_btn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_below="@id/main_tv"
        android:layout_marginTop="10dp"
        android:textAllCaps="false"
        android:textSize="20sp"
        android:text="Get My Location"/>
</RelativeLayout>

Activity接口：

//IMainActivity
public interface IMainActivity {
    void updateMyLocation(String location);
}

Activity实现：

//MainActivity
public class MainActivity extends Activity implements IMainActivity {
    private TextView mMain_tv;
    private Button mMain_btn;
    private IMainPresenter mMainPresenter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mMainPresenter = new MainPresenter(this);
        initView();
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        mMainPresenter.onDestroy();
        mMainPresenter = null;
    }

    private void initView() {
        mMain_tv = (TextView)findViewById(R.id.main_tv);
        mMain_btn = (Button)findViewById(R.id.main_btn);
        mMain_btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                getMyLocation();
            }
        });
    }

    private void getMyLocation() {
        mMainPresenter.getMyLocation();
    }

    @Override
    public void updateMyLocation(String location) {
        mMain_tv.setText(location);
    }
}

三、Presenter层

Presenter接口：

//IMainPresenter
public interface IMainPresenter {
    void getMyLocation();
    void onDestroy();
}

Presenter实现：

//MainPresenter
public class MainPresenter implements IMainPresenter{
    private IDataManager mDataManager;
    private IMainActivity mMainActivity;

    public MainPresenter(IMainActivity mainActivity) {
        mMainActivity = mainActivity;
        mDataManager = new DataManager();
    }

    @Override
    public void getMyLocation() {
        String location = mDataManager.getMyLocation();
        mMainActivity.updateMyLocation(location);
    }

    @Override
    public void onDestroy() {
        mMainActivity = null;
        mDataManager = null;
    }
}