无法设置API 21和22中Android Spinner弹出窗口的高度

在这里,我用了一些风格的“纺纱机”。为了设置微调器弹出窗口的高度,我使用了“列表弹出窗口”。对于更多的Android版本来说,它工作得很好。但不支持API 21和22(Android 5.0和5.1)。下面是我从中找到的代码 How to limit the height of Spinner drop down view in Android

Spinner newsSourceSpinner = (Spinner)findViewById(R.id.news_spinner);

try {
    Field popup = Spinner.class.getDeclaredField("mPopup");
    popup.setAccessible(true);

    // Get private mPopup member variable and try cast to ListPopupWindow
    android.widget.ListPopupWindow popupWindow = (android.widget.ListPopupWindow) popup.get(newsSourceSpinner);

    // set popup height
    popupWindow.setHeight(250);

} catch (NoClassDefFoundError | ClassCastException | NoSuchFieldException | IllegalAccessException e) {
    // silently fail...
}

活动\u main.xml

<Spinner
       android:id="@+id/news_spinner"
       android:layout_width="match_parent"
       android:layout_height="match_parent"
       android:textSize="13sp"
       style="@style/Widget.AppCompat.Spinner.Underlined"
       android:theme="@style/SpinnerStyle"
       android:popupBackground="#80000000"
       android:focusableInTouchMode="true"
       android:focusable="true"/>

样式.xml

<style name="SpinnerStyle">
    <item name="colorControlNormal">@color/colorWhite</item>
</style>