如何使用配置活动创建应用小部件,并首次更新它？

Question

这真让我抓狂.即使使用推荐的做法,我也不知道如何从配置活动更新app小部件.为什么不在应用程序小部件创建上调用更新方法超出了我的理解.

我想要的是:包含项目集合(带有列表视图)的应用程序小部件.但是用户需要选择一些东西,所以我需要一个配置活动.

配置活动是ListActivity:

@TargetApi(Build.VERSION_CODES.HONEYCOMB)
public class ChecksWidgetConfigureActivity extends SherlockListActivity {
    private List<Long> mRowIDs;
    int mAppWidgetId = AppWidgetManager.INVALID_APPWIDGET_ID;
    private BaseAdapter mAdapter;

    @Override
    protected void onCreate(final Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setResult(RESULT_CANCELED);
        setContentView(R.layout.checks_widget_configure);

        final Intent intent = getIntent();
        final Bundle extras = intent.getExtras();
        if (extras != null) {
            mAppWidgetId = extras.getInt(AppWidgetManager.EXTRA_APPWIDGET_ID, AppWidgetManager.INVALID_APPWIDGET_ID);
        }

        // If they gave us an intent without the widget id, just bail.
        if (mAppWidgetId == AppWidgetManager.INVALID_APPWIDGET_ID) {
            finish();
        }

        mRowIDs = new ArrayList<Long>(); // it's actually loaded from an ASyncTask, don't worry about that — it works.
        mAdapter = new MyListAdapter((LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE));
        getListView().setAdapter(mAdapter);
    }

    private class MyListAdapter extends BaseAdapter {
        // not relevant...
    }

    @Override
    protected void onListItemClick(final ListView l, final View v, final int position, final long id) {
        if (position < mRowIDs.size()) {
            // Set widget result
            final Intent resultValue = new Intent();
            resultValue.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, mAppWidgetId);
            resultValue.putExtra("rowId", mRowIDs.get(position));
            setResult(RESULT_OK, resultValue);

            // Request widget update
            final AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(this);
            ChecksWidgetProvider.updateAppWidget(this, appWidgetManager, mAppWidgetId, mRowIDs);
        }

        finish();
    }
}

正如您所看到的,我正在从我的应用小部件提供商处调用静态方法.我从官方文件中得到了这个想法.

我们来看看我的提供者:

@TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
public class ChecksWidgetProvider extends AppWidgetProvider {
    public static final String TOAST_ACTION = "com.example.android.stackwidget.TOAST_ACTION";
    public static final String EXTRA_ITEM = "com.example.android.stackwidget.EXTRA_ITEM";

    @Override
    public void onUpdate(final Context context, final AppWidgetManager appWidgetManager, final int[] appWidgetIds) {
        super.onUpdate(context, appWidgetManager, appWidgetIds);
        final int N = appWidgetIds.length;

        // Perform this loop procedure for each App Widget that belongs to this provider
        for (int i = 0; i < N; i++) {
            // Here we setup the intent which points to the StackViewService which will
            // provide the views for this collection.
            final Intent intent = new Intent(context, ChecksWidgetService.class);
            intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetIds[i]);
            // When intents are compared, the extras are ignored, so we need to embed the extras
            // into the data so that the extras will not be ignored.
            intent.setData(Uri.parse(intent.toUri(Intent.URI_INTENT_SCHEME)));
            final RemoteViews rv = new RemoteViews(context.getPackageName(), R.layout.checks_widget);
            rv.setRemoteAdapter(android.R.id.list, intent);

            // The empty view is displayed when the collection has no items. It should be a sibling
            // of the collection view.
            rv.setEmptyView(android.R.id.list, android.R.id.empty);

            // Here we setup the a pending intent template. Individuals items of a collection
            // cannot setup their own pending intents, instead, the collection as a whole can
            // setup a pending intent template, and the individual items can set a fillInIntent
            // to create unique before on an item to item basis.
            final Intent toastIntent = new Intent(context, ChecksWidgetProvider.class);
            toastIntent.setAction(ChecksWidgetProvider.TOAST_ACTION);
            toastIntent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetIds[i]);
            toastIntent.setData(Uri.parse(toastIntent.toUri(Intent.URI_INTENT_SCHEME)));
            final PendingIntent toastPendingIntent = PendingIntent.getBroadcast(context, 0, toastIntent, PendingIntent.FLAG_UPDATE_CURRENT);
            rv.setPendingIntentTemplate(android.R.id.list, toastPendingIntent);

            appWidgetManager.updateAppWidget(appWidgetIds[i], rv);
        }
    }

    @Override
    public void onReceive(final Context context, final Intent intent) {
        final AppWidgetManager mgr = AppWidgetManager.getInstance(context);
        if (intent.getAction().equals(TOAST_ACTION)) {
            final int appWidgetId = intent.getIntExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, AppWidgetManager.INVALID_APPWIDGET_ID);
            final long rowId = intent.getLongExtra("rowId", 0);
            final int viewIndex = intent.getIntExtra(EXTRA_ITEM, 0);
            Toast.makeText(context, "Touched view " + viewIndex + " (rowId: " + rowId + ")", Toast.LENGTH_SHORT).show();
        }
        super.onReceive(context, intent);
    }

    @Override
    public void onAppWidgetOptionsChanged(final Context context, final AppWidgetManager appWidgetManager, final int appWidgetId, final Bundle newOptions) {
        updateAppWidget(context, appWidgetManager, appWidgetId, newOptions.getLong("rowId"));
    }

    public static void updateAppWidget(final Context context, final AppWidgetManager appWidgetManager, final int appWidgetId, final long rowId) {
        final RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.checks_widget);
        appWidgetManager.updateAppWidget(appWidgetId, views);
    }
}

这基本上是官方文档的复制/粘贴.我们可以在这里看到我的静态方法.让我们假装它实际上使用了rowIdfor now.

我们还可以看到另一个失败(见下文)尝试在收到选项change broadcast(onAppWidgetOptionsChanged)时更新app小部件.

在Service基于集合的应用程序插件需要的是DOC的几乎精确的复制/粘贴:

@TargetApi(Build.VERSION_CODES.HONEYCOMB)
public class ChecksWidgetService extends RemoteViewsService {
    @Override
    public RemoteViewsFactory onGetViewFactory(final Intent intent) {
        return new StackRemoteViewsFactory(this.getApplicationContext(), intent);
    }
}

class StackRemoteViewsFactory implements RemoteViewsService.RemoteViewsFactory {
    private static final int mCount = 10;
    private final List<WidgetItem> mWidgetItems = new ArrayList<WidgetItem>();
    private final Context mContext;
    private final int mAppWidgetId;
    private final long mRowId;

    public StackRemoteViewsFactory(final Context context, final Intent intent) {
        mContext = context;
        mAppWidgetId = intent.getIntExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, AppWidgetManager.INVALID_APPWIDGET_ID);
        mRowId = intent.getLongExtra("rowId", 0);
    }

    @Override
    public void onCreate() {
        // In onCreate() you setup any connections / cursors to your data source. Heavy lifting,
        // for example downloading or creating content etc, should be deferred to onDataSetChanged()
        // or getViewAt(). Taking more than 20 seconds in this call will result in an ANR.
        for (int i = 0; i < mCount; i++) {
            mWidgetItems.add(new WidgetItem(i + " (rowId: " + mRowId + ") !"));
        }

        // We sleep for 3 seconds here to show how the empty view appears in the interim.
        // The empty view is set in the StackWidgetProvider and should be a sibling of the
        // collection view.
        try {
            Thread.sleep(3000);
        } catch (final InterruptedException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void onDestroy() {
        // In onDestroy() you should tear down anything that was setup for your data source,
        // eg. cursors, connections, etc.
        mWidgetItems.clear();
    }

    @Override
    public int getCount() {
        return mCount;
    }

    @Override
    public RemoteViews getViewAt(final int position) {
        // position will always range from 0 to getCount() - 1.

        // We construct a remote views item based on our widget item xml file, and set the
        // text based on the position.
        final RemoteViews rv = new RemoteViews(mContext.getPackageName(), R.layout.widget_item);
        rv.setTextViewText(R.id.widget_item, mWidgetItems.get(position).text);

        // Next, we set a fill-intent which will be used to fill-in the pending intent template
        // which is set on the collection view in StackWidgetProvider.
        final Bundle extras = new Bundle();
        extras.putInt(ChecksWidgetProvider.EXTRA_ITEM, position);
        final Intent fillInIntent = new Intent();
        fillInIntent.putExtras(extras);
        rv.setOnClickFillInIntent(R.id.widget_item, fillInIntent);

        // You can do heaving lifting in here, synchronously. For example, if you need to
        // process an image, fetch something from the network, etc., it is ok to do it here,
        // synchronously. A loading view will show up in lieu of the actual contents in the
        // interim.
        try {
            L.d("Loading view " + position);
            Thread.sleep(500);
        } catch (final InterruptedException e) {
            e.printStackTrace();
        }

        // Return the remote views object.
        return rv;
    }

    @Override
    public RemoteViews getLoadingView() {
        // You can create a custom loading view (for instance when getViewAt() is slow.) If you
        // return null here, you will get the default loading view.
        return null;
    }

    @Override
    public int getViewTypeCount() {
        return 1;
    }

    @Override
    public long getItemId(final int position) {
        return position;
    }

    @Override
    public boolean hasStableIds() {
        return true;
    }

    @Override
    public void onDataSetChanged() {
        // This is triggered when you call AppWidgetManager notifyAppWidgetViewDataChanged
        // on the collection view corresponding to this factory. You can do heaving lifting in
        // here, synchronously. For example, if you need to process an image, fetch something
        // from the network, etc., it is ok to do it here, synchronously. The widget will remain
        // in its current state while work is being done here, so you don't need to worry about
        // locking up the widget.
    }
}

最后,我的小部件布局:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/widgetLayout"
    android:orientation="vertical"
    android:padding="@dimen/widget_margin"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/resizeable_widget_title"
        style="@style/show_subTitle"
        android:padding="2dp"
        android:paddingLeft="5dp"
        android:textColor="#FFFFFFFF"
        android:background="@drawable/background_pink_striked_transparent"
        android:text="@string/show_title_key_dates" />

    <ListView
        android:id="@android:id/list"
        android:layout_marginRight="5dp"
        android:layout_marginLeft="5dp"
        android:background="@color/timeline_month_dark"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <TextView
        android:id="@android:id/empty"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center"
        android:textColor="#ffffff"
        android:textStyle="bold"
        android:text="@string/empty_view_text"
        android:textSize="20sp" />

</LinearLayout>

我的android清单XML文件的相关部分:

<receiver android:name="com.my.full.pkg.ChecksWidgetProvider">
    <intent-filter>
            <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
    </intent-filter>

    <meta-data
            android:name="android.appwidget.provider"
            android:resource="@xml/checks_widget_info" />
</receiver>
<activity android:name="com.my.full.pkg.ChecksWidgetConfigureActivity">
    <intent-filter>
            <action android:name="android.appwidget.action.APPWIDGET_CONFIGURE" />
    </intent-filter>
</activity>
<service
    android:name="com.my.full.pkg.ChecksWidgetService"
    android:permission="android.permission.BIND_REMOTEVIEWS" />

xml/checks_widget_info.xml:

<?xml version="1.0" encoding="utf-8"?>
<appwidget-provider
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:minWidth="146dp"
    android:minHeight="146dp"
    android:updatePeriodMillis="86400000"
    android:initialLayout="@layout/checks_widget"
    android:configure="com.my.full.pkg.ChecksWidgetConfigureActivity"
    android:resizeMode="horizontal|vertical"
    android:previewImage="@drawable/resizeable_widget_preview" />

---

那么,怎么了？好吧,当我创建小部件时,它是空的.我的意思是无效.空.没有.我的布局中没有定义空视图!我勒个去？

如果我重新安装应用程序或重启设备(或杀死启动器应用程序),应用程序窗口小部件实际上已更新,并包含自动添加的10个项目,如示例中所示.

在配置活动完成后,我无法更新该死的东西.这个从doc开始的句子超出了我的范围:" 创建App Widget时不会调用onUpdate()方法 - 它只会在第一次跳过. "

我的问题是:

• 为什么Android开发团队在第一次创建窗口小部件时选择不调用更新？
• 如何在配置活动完成之前更新我的应用小部件？

我不理解的另一件事是行动流程:

1. 使用编译的最后一个代码安装应用程序,在启动器上准备空间,从启动器打开"小部件"菜单
2. 选择我的小部件并将其放置到所需的区域
3. 那时,我的应用小部件提供商收到android.appwidget.action.APPWIDGET_ENABLED然后android.appwidget.action.APPWIDGET_UPDATE
4. 然后我的app小部件提供程序获取其onUpdate方法调用.我希望在配置活动完成后发生这种情况......
5. 我的配置活动开始了.但是app小部件似乎已经创建并更新了,我不明白.
6. 我从配置活动中选择项目:onListItemClick被调用
7. updateAppWidget调用我的提供程序的静态,拼命尝试更新小部件.
8. 配置活动设置其结果并完成.
9. 提供者收到android.appwidget.action.APPWIDGET_UPDATE_OPTIONS:嗯,在创建时接收大小更新确实很有意义.那是我拼命打电话的地方updateAppWidget
10. onUpdate从我的提供者不被调用.为什么？？!!

最后:小部件是空的.不是listview-empty或@android:id/empty-empty,真的是EMPTY.没有显示视图.没有.
如果我再次安装应用程序,应用程序窗口小部件将按照预期填充列表视图中的视图.
调整窗口小部件的大小无效.它只是onAppWidgetOptionsChanged再次调用,没有任何效果.

我的意思是空:app小部件布局是膨胀的,但列表视图不会膨胀,并且不显示空视图.

Answer 1

通过AppWidgetManager进行更新的缺点是你必须提供RemoteViews - 从设计的角度来看 - 没有意义,因为与RemoteViews相关的逻辑应该被封装在AppWidgetProvider中(或者在你的情况下) RemoteViewsService.RemoteViewsFactory).

SciencyGuy通过静态方法公开RemoteViews逻辑的方法是解决这个问题的一种方法,但是有一个更优雅的解决方案直接向窗口小部件发送广播:

Intent intent = new Intent(AppWidgetManager.ACTION_APPWIDGET_UPDATE, null, this, ChecksWidgetProvider.class);
intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_IDS, new int[] {mAppWidgetId});
sendBroadcast(intent);

因此,将调用AppWidgetProvider的onUpdate()方法来为窗口小部件创建RemoteView.

Answer 2

您在配置活动完成后未触发onUpdate方法是正确的.由配置活动决定是否进行初始更新.所以你需要构建初始视图.

这是在配置结束时应该做的事情的要点:

// First set result OK with appropriate widgetId
Intent resultValue = new Intent();
resultValue.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetId);
setResult(RESULT_OK, resultValue);

// Build/Update widget
AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(getApplicationContext());

// This is equivalent to your ChecksWidgetProvider.updateAppWidget()    
appWidgetManager.updateAppWidget(appWidgetId,
                                 ChecksWidgetProvider.buildRemoteViews(getApplicationContext(),
                                                                       appWidgetId));

// Updates the collection view, not necessary the first time
appWidgetManager.notifyAppWidgetViewDataChanged(appWidgetId, R.id.notes_list);

// Destroy activity
finish();

您已经正确设置了结果.并且您调用ChecksWidgetProvider.updateAppWidget(),但是updateAppWidget()不会返回正确的结果.

当前的updateAppWidget()返回一个空的RemoteViews对象.这解释了为什么您的小部件最初是完全空的.你没有用任何东西填充视图.我建议您将代码从onUpdate移动到静态buildRemoteViews()方法,您可以从onUpdate和updateAppWidget()调用它们:

public static RemoteViews buildRemoteViews(final Context context, final int appWidgetId) {
        final RemoteViews rv = new RemoteViews(context.getPackageName(), R.layout.checks_widget);
        rv.setRemoteAdapter(android.R.id.list, intent);

        // The empty view is displayed when the collection has no items. It should be a sibling
        // of the collection view.
        rv.setEmptyView(android.R.id.list, android.R.id.empty);

        // Here we setup the a pending intent template. Individuals items of a collection
        // cannot setup their own pending intents, instead, the collection as a whole can
        // setup a pending intent template, and the individual items can set a fillInIntent
        // to create unique before on an item to item basis.
        final Intent toastIntent = new Intent(context, ChecksWidgetProvider.class);
        toastIntent.setAction(ChecksWidgetProvider.TOAST_ACTION);
        toastIntent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetId);
        toastIntent.setData(Uri.parse(toastIntent.toUri(Intent.URI_INTENT_SCHEME)));
        final PendingIntent toastPendingIntent = PendingIntent.getBroadcast(context, 0, toastIntent, PendingIntent.FLAG_UPDATE_CURRENT);
        rv.setPendingIntentTemplate(android.R.id.list, toastPendingIntent);

        return rv;
}

public static void updateAppWidget(final Context context, final AppWidgetManager appWidgetManager, final int appWidgetId) {
    final RemoteViews views = buildRemoteViews(context, appWidgetId);
    appWidgetManager.updateAppWidget(appWidgetId, views);
}

@Override
public void onUpdate(final Context context, final AppWidgetManager appWidgetManager, final int[] appWidgetIds) {
    super.onUpdate(context, appWidgetManager, appWidgetIds);

    // Perform this loop procedure for each App Widget that belongs to this provider
    for (int appWidgetId: appWidgetIds) {
        RemoteViews rv = buildRemoteViews(context, appWidgetId);
        appWidgetManager.updateAppWidget(appWidgetIds[i], rv);
    }
}

这应该照顾小部件初始化.

在我的示例代码中调用finish()之前的最后一步是更新集合视图.正如评论所说,这是第一次没有必要.但是,我将其包括在内,以防您在添加小部件后允许重新配置小部件.在这种情况下,必须手动更新集合视图以确保加载适当的视图和数据.