您忘记设置要使用的远程视图。AppWidgetProvider的代码应该是:
public class Test extends AppWidgetProvider {
public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds){
super.onUpdate(context, appWidgetManager, appWidgetIds);
RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.test_layout);
views.setTextViewText(R.id.TextView01, "Test message");
appWidgetManager.updateAppWidget(appWidgetIds, views);
}
}