应用小部件未显示在Oreo上

Question

Instead, the widget area displays an error message saying "Problem while loading widget"

In the log, I see these errors when adding the app widget :

07-24 15:57:24.651 2057-5433/? E/RemoteViews: Package name com.theapp not found

07-24 15:57:24.651 2057-2057/? W/AppWidgetHostView: updateAppWidget couldn't find any view, using error view
    android.content.res.Resources$NotFoundException: Resource ID #0x7f0b0034 type #0x5 is not valid
        at android.content.res.Resources.loadXmlResourceParser(Resources.java:2139)
        at android.content.res.Resources.getLayout(Resources.java:1143)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:421)
        at android.widget.RemoteViews.inflateView(RemoteViews.java:3498)
        at android.widget.RemoteViews.-wrap1(Unknown Source:0)
        at android.widget.RemoteViews$AsyncApplyTask.doInBackground(RemoteViews.java:3600)
        at android.widget.RemoteViews$AsyncApplyTask.doInBackground(RemoteViews.java:3596)
        at android.os.AsyncTask$2.call(AsyncTask.java:333)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636)
        at java.lang.Thread.run(Thread.java:764)

The widget displays fine on Android versions pre 8

EDIT: Here is my widget layout file:

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

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@drawable/appwidget_background"
        android:orientation="horizontal">

        <TextView
            android:id="@+id/button_settings"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="@string/app_name" />

        <TextView
            android:id="@+id/button_on"
            android:layout_width="56dp"
            android:layout_height="match_parent"
            android:text="@string/on" />

        <TextView
            android:id="@+id/button_off"
            android:layout_width="56dp"
            android:layout_height="match_parent"
            android:text="@string/off" />
    </LinearLayout>
</FrameLayout>

and meta data file:

<?xml version="1.0" encoding="utf-8"?>
<appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android"
    android:minWidth="40dp"
    android:minHeight="40dp"
    android:updatePeriodMillis="0"
    android:previewImage="@drawable/widget_preview"
    android:configure="com.theapp.appwidget.AppWidgetActivity"
    android:initialLayout="@layout/appwidget"
    android:resizeMode="horizontal|vertical" />

Answer 1

"Problem while loading widget" + your limited stacktrace indicate a layout problem. It would help if you showed your layout file. Go back and check all your attributes, images and views. There may be an element to your layout that isn't allowed for an appwidget as they are restricted in what views can be used. Also check that you sized your widget properly in the metadata xml file, and check that your padding follows the guidelines. The android guideline describes how you should size it and use padding: https://developer.android.com/guide/practices/ui_guidelines/widget_design