没有调用onActivityResult

Question

我在阅读多个网页后尝试了很多方法，但是，我无法在两个活动和一个片段之间进行对象的往返。

概述：该对象是描述膳食的Serializable对象（您吃的东西）。我有一个MainActivity使用片段，ListView列出了Meal对象。当我点击ListView中的一餐时，使用 startActivityForResult 方法启动MealEditorActivity。这很好用。我可以在此活动中编辑Meal对象。

问题：当我在MealEditorActivity菜单栏中单击后，我想要重新发送已编辑的Meal对象，但片段中的 onActivityResult 和MainActivity中都没有被称为。

我做错了什么？

代码段：

... 
public class MainActivity extends AppCompatActivity {
    private static final String LOG_TAG = MainActivity.class.getSimpleName();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // add a button below the listview to create new Meal entries
        Button newButton = (Button) findViewById(R.id.new_meal_button);
        newButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
               ...
            }
        });
    } 
   ...

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        Log.d(LOG_TAG, "onActivityResult in MainActivity triggered");
        super.onActivityResult(requestCode, resultCode, data);
    }
}

这就是单击一份用餐时片段中MealEditorActivity的启动方式..

...
public class MainFragmentMealList extends Fragment {

private static final String LOG_TAG = MainFragmentMealList.class.getSimpleName();

protected List<Meal> mealList;

protected final int REQUEST_CODE = 1;

public MainFragmentMealList() {}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {

    mealList = new ArrayList<Meal>();

    // if no data exists in database, the generate some test data
    if(mealList.size() == 0) {
        Meal meal = new Meal();
        meal.setId(mealList.size()+1);
        meal.test();
        mealList.add(meal);
        meal = new Meal();
        meal.setId(mealList.size()+1);
        meal.test2();
        mealList.add(meal);
    }

    ArrayAdapter<Meal> mealListeAdapter =
            new ArrayAdapter<>(
                    getActivity(), // Die aktuelle Umgebung (diese Activity)
                    R.layout.meal_list_item, // ID der XML-Layout Datei
                    R.id.meal_list_item_textview, // ID des TextViews
                    mealList); // Beispieldaten in einer ArrayList

    View rootView = inflater.inflate(R.layout.fragment_meallist_main, container, false);

    ListView mealListView = (ListView) rootView.findViewById(R.id.listview_mealliste);
    mealListView.setAdapter(mealListeAdapter);

    mealListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, int position, long id) {
            Meal selMeal = (Meal) adapterView.getItemAtPosition(position);
            Intent intent = new Intent(getActivity(), MealEditorActivity.class);
            Bundle bundle = new Bundle();
            bundle.putSerializable(MealEditorActivity.EDIT_MEAL_TAG, selMeal);
            intent.putExtras(bundle);
            startActivityForResult(intent, REQUEST_CODE);
        }
    });

    return rootView;
}

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {

        Log.d(LOG_TAG, "onActivityResult triggered: " + requestCode);

        if (resultCode == Activity.RESULT_OK) {
            Meal meal = (Meal) data.getExtras().getSerializable(MealEditorActivity.REPLY_MEAL_TAG);
            Log.d(LOG_TAG, "Date@onActivityResult : " + meal.getDate());            
    }

    super.onActivityResult(requestCode, resultCode, data);
}
...   

MealEditorActivity，应该从finish方法发送结果..

...
public class MealEditorActivity extends AppCompatActivity {

    private static final String LOG_TAG = MealEditorActivity.class.getSimpleName();

    public static final String EDIT_MEAL_TAG = "EDIT_MEAL";
    public static final String REPLY_MEAL_TAG = "REPLY_MEAL";

    protected Meal meal;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_editor_meal);

        // get the meal object from the MainActivity to be edited
        Intent intent = getIntent();
        meal = (Meal) intent.getSerializableExtra(EDIT_MEAL_TAG);

        // initialize widgets in the view with data from meal object
        // and create listeners to update the meal object with user edits
        ...
     }

    @Override
    public void finish() {
        Log.d(LOG_TAG, "Date@finish : " + meal.getDate());
        Intent resultIntent = new Intent();
        resultIntent.putExtra(MealEditorActivity.REPLY_MEAL_TAG, meal);
        setResult(RESULT_OK, resultIntent);
        super.finish();
    }

    @Override
    public void onBackPressed() {
        finish();
        super.onBackPressed();
    }

    // This one is triggered if the back button is clicked in the menu
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        finish();
        return super.onOptionsItemSelected(item);
    }

}

这是AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.levin.symptomdiary">

    <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"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".MealEditorActivity"
            android:label="@string/action_editor_name"
            android:parentActivityName=".MainActivity" >
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value="com.levin.symptomdiary.MainActivity" />
        </activity>
    </application>

</manifest>

我使用新安装的Android Studio与移动Emulator，Android 4.4目标。

这是我的第一个Android开发，因此，任何帮助都非常感谢。非常感谢你提前!!