In the below example code I have created a Custom Spinner. Here first, I have added spinner library in build.gradle file. After that, I have added Spinner layout in activity_main.xml layout. In MainActivity I have added items name in String.

You can see below example code it clearly describes "How to make Custom Spinner using spinner material design library?".

Step(1)-I have added first material design spinner dependency to Grandle file -

Introduction of library:- There is a material design spinner library which provides us the facility to create or to add a customize spinner in your application.

     compile 'com.weiwangcn.betterspinner:library-material:1.1.0'

Step(2)-Added spinner layout in activity_main.xml-

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_margin="16dp"
    android:orientation="vertical">

    <com.weiwangcn.betterspinner.library.material.MaterialBetterSpinner
        android:id="@+id/android_material_design_spinner"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Company Name "
        android:textColorHint="#d10e3b"
        app:met_floatingLabel="normal" />
</LinearLayout>

Step(3)-MainActivity-

In MainActivity I have added Company  names in String array List then I have created ArrayAdapter for using String Array list

public class MainActivity extends AppCompatActivity {

        String[] SPINNERLIST = {"Evon tech", "Microsoft", "Ericsson", "Genpack"};

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);

            ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(this,
                    android.R.layout.simple_spinner_dropdown_item, SPINNERLIST);
            MaterialBetterSpinner materialDesignSpinner = (MaterialBetterSpinner)
                    findViewById(R.id.android_material_design_spinner);
            materialDesignSpinner.setAdapter(arrayAdapter);
        }
    }