单击窗口小部件onUpdate时未调用

Question

我有一个小部件，希望它在单击时打开活动。这是场景：用户应该能够向小部件添加配方，这样，如果单击小部件，它将打开包含该配方的活动。 我注意到小部件类中的onUpdate回调仅在应用启动时被调用一次。

这是我的活动代码（我将食谱保存在SharedPreferences中，以便小部件在要使用该食谱数据打开活动时可以检索其数据）：

public class RecipeDetailsActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.recipe_details);
        FloatingActionButton floatingActionButton = findViewById(R.id.recipe_fab);
        floatingActionButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                storeRecipe(ingredients, steps);
                Intent intent = new Intent(RecipeDetailsActivity.this, RecipeWidget.class);
                intent.setAction(AppWidgetManager.ACTION_APPWIDGET_UPDATE);

                AppWidgetManager widgetManager = AppWidgetManager.getInstance(RecipeDetailsActivity.this);
                int [] ids = widgetManager.getAppWidgetIds(new ComponentName(getApplication(), RecipeWidget.class));
                intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, ids);
                sendBroadcast(intent);

                Toast.makeText(RecipeDetailsActivity.this, "clicked", Toast.LENGTH_LONG).show();
            }
        });
    }

    private void storeRecipe (ArrayList <Ingredient> ingredients, ArrayList <Step> steps){
        //The Gson trick is obtained from here: https://www.youtube.com/watch?v=jcliHGR3CHo

        //Convert the ingredients and steps to Json string using Gson library so we can store those strings in SharedPreferences:
        Gson GsonObj = new Gson();
        String ingredientsJson = GsonObj.toJson(ingredients);
        String stepsJson = GsonObj.toJson(steps);
        //Store the data in SahredPreferences
        SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
        SharedPreferences.Editor editor = sharedPreferences.edit();
        editor.putString("ingredients", ingredientsJson).apply();
        editor.putString("steps", stepsJson).apply();
    }
}

这是我的AppWidget Java类：

public class RecipeWidget extends AppWidgetProvider {

    static ArrayList <Ingredient> ingredients;
    static ArrayList <Step> steps;

    static void updateAppWidget(Context context, AppWidgetManager appWidgetManager,
                                int appWidgetId) {

        // To add interaction through the widget, construct a remoteviews object and associate it with the widget layout
        RemoteViews remoteViews = new RemoteViews(context.getPackageName(), R.layout.recipe_widget);

        //Create an intent that will open the details (ingredients and steps) for the desired recipe, then add it to a pending intent that will be fired when the widget is clicked
        Intent intent = new Intent (context, RecipeDetailsActivity.class);

        //Load the ArrayLists of the steps and ingredients of the selected recipe from SharedPrefs
        loadRecipe(context);

        //Prepare a bundle to add it to the pending intent
        Bundle bundle = new Bundle();
        bundle.putParcelableArrayList("ingredients", ingredients);
        bundle.putParcelableArrayList("steps", steps);

        PendingIntent pendingIntent = PendingIntent.getActivity(context, 0, intent, 0, bundle);

        remoteViews.setOnClickPendingIntent(appWidgetId, pendingIntent);

        // Instruct the widget manager to update the widget
        appWidgetManager.updateAppWidget(appWidgetId, remoteViews);
    }

    @Override
    public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
        // There may be multiple widgets active, so update all of them
        Log.i("msg", "on update is called");
        for (int appWidgetId : appWidgetIds) {
            updateAppWidget(context, appWidgetManager, appWidgetId);
        }
    }

    static private void loadRecipe (Context context){
        //The Gson trick is obtained from here: https://www.youtube.com/watch?v=jcliHGR3CHo
        SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(context);
        String ingredientsString = sharedPreferences.getString("ingredients", null);
        String stepsString = sharedPreferences.getString("steps", null);

        //Convert the ingredients and steps from Strings to ArrayLists:
        Gson GsonObj = new Gson();
        Type ingredientsType = new TypeToken<ArrayList<Ingredient>>() {}.getType();
        Type stepsType = new TypeToken<ArrayList<Step>>() {}.getType();

        ingredients = GsonObj.fromJson(ingredientsString, ingredientsType);
        steps = GsonObj.fromJson(stepsString, stepsType);
    }
}

最后，这是清单中定义窗口小部件的方式：

 <receiver android:name=".widgets.RecipeWidget">
            <intent-filter>
                <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
                <action android:name="com.example.backingapp.RecipeWidget.ACTION_CLICK"/>
            </intent-filter>

            <meta-data
                android:name="android.appwidget.provider"
                android:resource="@xml/recipe_widget_info" />
        </receiver>

我将不胜感激。 谢谢。