You need to set background of spinner as follows:
In your layout xml :
<Spinner
android:id="@+id/spinner1"
style="@style/spinner_style"
android:layout_width="match_parent"
android:layout_gravity="center_vertical"
android:gravity="center_vertical"
android:layout_height="45dp" />
Now in style.xml add a style for spinner as follows:
` <style name="spinner_style">
<item name="android:background">@drawable/spinner_bg</item>
<!--
<item name="android:layout_marginLeft">10dp</item>
<item name="android:layout_marginRight">10dp</item>
<item name="android:layout_marginBottom">10dp</item>
<item name="android:paddingLeft">8dp</item>
<item name="android:paddingTop">5dp</item>
<item name="android:paddingBottom">5dp</item>
-->
<item name="android:paddingLeft">5</item>
</style>`
Now make a xml named spinner_bg.xml in drawable :
`
<item><layer-list>
<item><shape>
<gradient android:angle="90" android:endColor="@android:color/transparent" android:startColor="@android:color/transparent" android:type="linear" />
<padding android:left="2dp" android:right="2dp" />
</shape></item>
<item>
<bitmap android:gravity="center_vertical|left" android:src="your background drawable for spinner here" />
</item>
</layer-list></item>
`
According to your question, below part of spinner_bg.xml did the trick.
`<item>
<bitmap android:gravity="center_vertical|left" android:src="your background drawable for spinner here" />
</item>`
Thats it.