为什么我的小部件没有加载在冰淇淋三明治上

Question

所以这是我的WidgetProvider

    public class MessagesWidgetProvider extends AppWidgetProvider {

    public static final String EXTRA_WIDGET_MESSAGE = "widget_message";
    public static final String EXTRA_WIDGET_ID = "widget_id";

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

    private static void updateWidget(Context context, int[] appWidgetIds,
            AppWidgetManager appWidgetManager) {
        ForwardingMessage[] allMessages = ForwardingMessage.getAllMessages();
        RemoteViews views = null;
        if (allMessages.length == 0) {
            views = new RemoteViews(context.getPackageName(),
                    R.layout.messages_widget_layout);
            views.setTextViewText(R.id.profileNameTextView,
                    context.getString(R.string.no_messages_to_show));
            views.setTextViewText(R.id.messageContentTextView, "");
            appWidgetManager.updateAppWidget(appWidgetIds, views);
        } else {
            ForwardingMessage latestMessage = allMessages[allMessages.length - 1];
            for (int id : appWidgetIds) {
                views = generateViewsFromMessage(latestMessage, context, id);
                appWidgetManager.updateAppWidget(id, views);
            }
        }
    }

    private static RemoteViews generateViewsFromMessage(
            ForwardingMessage message, Context context, int widgetId) {
        RemoteViews views = new RemoteViews(context.getPackageName(),
                R.layout.messages_widget_layout);
        ForwardingMessage previous = message.getPreviousMessage();
        ForwardingMessage next = message.getNextMessage();
        views.setBoolean(R.id.previousButton, "setEnabled", previous != null);
        views.setBoolean(R.id.nextButton, "setEnabled", next != null);
        views.setTextViewText(R.id.profileNameTextView, message
                .getForwardingProfile().getName());
        views.setTextViewText(R.id.messageContentTextView, message.getText());
        // Let's start adding the listeners to the buttons
        if (previous != null) {
            Intent previousIntent = new Intent(ACTION_SHOW_WIDGET_MESSAGE);
            previousIntent.putExtra(EXTRA_WIDGET_MESSAGE, previous);
            previousIntent.putExtra(EXTRA_WIDGET_ID, widgetId);
            PendingIntent previousPendingIntent = PendingIntent.getBroadcast(
                    context, 0, previousIntent, PendingIntent.FLAG_ONE_SHOT
                            | PendingIntent.FLAG_CANCEL_CURRENT);
            views.setOnClickPendingIntent(R.id.previousButton,
                    previousPendingIntent);
        }
        // Now the next message
        if (next != null) {
            Intent nextIntent = new Intent(ACTION_SHOW_WIDGET_MESSAGE);
            nextIntent.putExtra(EXTRA_WIDGET_MESSAGE, next);
            nextIntent.putExtra(EXTRA_WIDGET_ID, widgetId);
            PendingIntent nextPendingIntent = PendingIntent.getBroadcast(
                    context, 1, nextIntent, PendingIntent.FLAG_ONE_SHOT
                            | PendingIntent.FLAG_CANCEL_CURRENT);
            views.setOnClickPendingIntent(R.id.nextButton, nextPendingIntent);
        }
        return views;
    }
}

这是小部件布局。

    <?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"
    android:background="#AA000000" android:layout_margin="10dp">

    <TextView
        android:id="@+id/profileNameTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:text="Medium Text"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <TextView
        android:id="@+id/messageContentTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/profileNameTextView"
        android:text="Small Text"
        android:textAppearance="?android:attr/textAppearanceSmall" android:textColor="#FFFFFF" android:layout_margin="5dp" android:scrollbars="vertical"/>

    <LinearLayout
        android:id="@+id/linearLayout1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true" >

        <Button
            android:id="@+id/previousButton"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="@string/previous" />

        <Button
            android:id="@+id/nextButton"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="@string/next" />
    </LinearLayout>

</RelativeLayout>

问题：

当allMessages数组的长度为零时，窗口小部件工作得很好：我将TextView的文本设置为“没有要显示的消息”，每个人都很开心;当我在数组中至少有一条消息时，代码运行得很好，没有异常，没有任何东西（我调试了它和所有东西）但是当onUpdate返回时，模拟器在主屏幕上显示“Problem loading widget”小部件应该在哪里。同样重要的是要注意相同的代码在Froyo和Gingerbread中工作得很好。如果出现问题，为什么我没有得到任何例外？调试器运行整个onUpdate方法并返回正常，但小部件不会加载。有什么想法吗？