Android Spinner不显示下拉箭头解决方案

转载自：爱编程的大狗 - Android Spinner 不显示下拉箭头

<Spinner
    android:layout_width="match_parent"
    android:layout_height="?attr/actionBarSize"
    android:background="@drawable/shape_drop_down_normal"
    android:dropDownSelector="@color/color_white"
    android:entries="@array/type_spinner" />

shape_drop_down_normal.xml

<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >
    <item>
        <shape>
            <stroke
                android:width="1dp"
                android:color="@color/color_white" />

            <padding
                android:bottom="10dp"
                android:left="2dp"
                android:right="10dp"
                android:top="10dp" />
        shape>
    item>
    <item>
        <bitmap
            android:gravity="end"
            android:src="@mipmap/arrow_down" />
    item>
layer-list>