How to put a border around MaterialSpinner Xamarin.Android? - xamarin.android

Question

I have to give my MaterialSpinner the following border:
I have the following MaterialSpinner
<fr.ganfra.materialspinner.MaterialSpinner
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/spinner"
app:ms_arrowColor="#000000"
app:ms_arrowSize="16dp"
app:ms_floatingLabelColor="#A9A9A9"
app:ms_floatingLabelText="Избор на група"
app:ms_hint="Избор на група"
app:ms_hintColor="#000000"
android:padding="10dp"
android:layout_gravity="center"
android:background="#drawable/material_spinner_border"/>
material_spinner_border.xml:
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle" >
<!-- View background color -->
<solid
android:color="#000000" >
</solid>
<!-- View border color and width -->
<stroke
android:width="1dp"
android:color="#000000" >
</stroke>
<!-- The radius makes the corners rounded -->
<corners
android:radius="2dp" >
</corners>
</shape>
When I run the app the border doesn't appear on screen

Answer 1

How to put a border around MaterialSpinner Xamarin.Android?
Set your MaterialSpinner ms_arrowColor color as white to hide the arrow:
<fr.ganfra.materialspinner.MaterialSpinner
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/spinner"
app:ms_floatingLabelColor="#A9A9A9"
app:ms_floatingLabelText="Избор на група"
app:ms_hint="Избор на група"
app:ms_hintColor="#000000"
app:ms_arrowColor="#ffffff"
app:ms_arrowSize="16dp"
android:background="#drawable/material_spinner_border"
android:layout_margin="5dp"
/>
Add your arrow image to your project, for example:
Then, modify your material_spinner_border like this:
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item>
<layer-list>
<item>
<shape>
<stroke android:width="3dp" android:color="#000000" />
<corners android:radius="4dp" />
<padding android:bottom="0dp" android:left="3dp" android:right="3dp" android:top="0dp" />
</shape>
</item>
<item >
<bitmap android:gravity="center|right" android:src="#drawable/myarrow" />
</item>
</layer-list>
</item>
</selector>
Effect.
Update:
Set spinner background after set the Spinner adapter will solve this issue:
string[] ITEMS = { "Item 1", "Item 2", "Item 3", "Item 4", "Item 5", "Item 6" };
var adapter = new ArrayAdapter<String>(this, Android.Resource.Layout.SimpleSpinnerItem, ITEMS);
adapter.SetDropDownViewResource(Android.Resource.Layout.SimpleSpinnerDropDownItem);
var spinner = FindViewById<MaterialSpinner>(Resource.Id.spinner);
spinner.Adapter = adapter;
spinner.Background = Drawable.CreateFromXml(Resources, Resources.GetXml(Resource.Drawable.material_spinner_border));

Answer 2

Here is a picture what it looks like:
I forgot to tell you that my backgroung is dark if it matters