如何在android中更改此黑色弹出窗口背景

Question

大家好，我正面临一个错误。我把它popupBackground="@color/white"放了。但是，我无法改变背后的弹出黑色。所以大家请帮我解决这个问题。

in .xml

<Spinner
                    android:id="@+id/spinner_Empgender"
                    android:layout_width="match_parent"
                    android:layout_height="45dp"
                    android:layout_marginBottom="10dp"
                    android:layout_weight="1"
                    android:background="@drawable/spinner_background"
                    android:clickable="true"
                    android:gravity="left"
                    android:popupBackground="@color/white"
                    android:spinnerMode="dropdown" />

in coading

    public void setGender_Data() {
    ArrayList<Static_Spinner_Data> GenderList = new ArrayList<>();
    GenderList.add(new Static_Spinner_Data("-1", "Select Gender"));
    GenderList.add(new Static_Spinner_Data("0", "Male"));
    GenderList.add(new Static_Spinner_Data("1", "Female"));
    GenderList.add(new Static_Spinner_Data("2", "Others"));
    ArrayAdapter<Static_Spinner_Data> Genderadapter = new ArrayAdapter<Static_Spinner_Data>(getContext(), R.layout.spinner_item, GenderList);
    Genderadapter.setDropDownViewResource(R.layout.spinner_item);
    spinner_Empgender.setAdapter(Genderadapter);
}

drawable / spinner_background

<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item>
    <color android:color="@color/white" />
</item>
<item android:gravity="center_vertical|right" android:right="1dp">
    <layer-list>
        <item android:width="12dp" android:height="12dp" android:gravity="center" android:bottom="10dp">
            <rotate
                android:fromDegrees="45"
                android:toDegrees="45">
                <shape android:shape="rectangle">
                    <stroke android:color="#000000" android:width="2dp"/>
                </shape>
            </rotate>
        </item>
        <item android:width="30dp" android:height="10dp" android:bottom="21dp" android:gravity="center">
            <shape android:shape="rectangle">
                <solid android:color="@color/white"/>
            </shape>
        </item>
    </layer-list>
</item>