How to create custom spinner like border around the spinner with down triangle on the right side?

Question

I want to develop custom spinner like line around spinner with triangle at right bottom corner.
like following image

Answer 1

This is a simple one.

your_layout.xml

<android.support.v7.widget.AppCompatSpinner
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:background="@drawable/spinner_background"
/>

In the drawable folder, spinner_background.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
  <item><layer-list>
    <item>
        <shape>
            <solid
                android:color="@color/colorWhite">
            </solid>

            <corners android:radius="3dp" />

            <padding
                android:bottom="10dp"
                android:left="10dp"
                android:right="10dp"
                android:top="10dp" />
            <stroke
                android:width="2dp"
                android:color="@color/colorDarkGrey"/>
        </shape>
    </item>
    <item >
        <bitmap android:gravity="bottom|right"
        android:src="@drawable/ic_arrow_drop_down_black_24dp" />
    </item>
  </layer-list></item>
</selector>

Preview: