Android AppWidget - 扩展视图时出错:无法解析索引处的属性

Android AppWidget - Error inflating view: Failed to resolve attribute at index

我有一个 AppWidget 产生了这个错误:

W/AppWidgetHostView: updateAppWidget couldn't find any view, using error view android.view.InflateException: Binary XML file line #2: Failed to resolve attribute at index 1: TypedValue{t=0x2/d=0x7f01009a a=-1} Caused by: java.lang.UnsupportedOperationException: Failed to resolve attribute at index 1: TypedValue{t=0x2/d=0x7f01009a a=-1}

我可以看出错误是由布局的 inflation 引起的,我可以将其归因于在我的 RemoteViewsService.RemoteViewsFactory 子类中创建新的 RemoteViews' getViewAt()方法:

@Override
public RemoteViews getViewAt(int position) {
    […]
    final RemoteViews views = new RemoteViews(getPackageName(),
            R.layout.appwidget_list_item);
    […]

    return views;
}

注释掉这一行可以消除这个特定的错误,但我无法弄清楚它引用的布局文件有什么问题。

布局文件:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:id="@+id/layout_view"
              android:orientation="horizontal"
              android:layout_width="match_parent"
              android:layout_height="?listPreferredItemHeight">

    <TextView
        android:id="@+id/item_name"
        android:layout_width="0px"
        android:layout_height="match_parent"
        android:layout_weight="2"
        android:gravity="center_vertical"
        android:paddingEnd="?listPreferredItemPaddingRight"
        android:paddingStart="?listPreferredItemPaddingLeft"/>

</LinearLayout>

该错误是由于在 AppWidget 布局中使用主题属性(例如 ?listPreferredItemHeight)引起的,isn't possible。这些是错误所指的 "unresolved attribute(s)"。