Android Spinner Example.

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <Spinner
        android:id="@+id/spinner1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="14dp" />

</RelativeLayout>

MainActivity.java

package com.mahi.spinner;

import android.os.Bundle;

import android.app.Activity;

import android.view.Menu;

import android.view.View;

import android.widget.AdapterView;

import android.widget.ArrayAdapter;

import android.widget.Spinner;

import android.widget.Toast;

public class MainActivity extends Activity implements AdapterView.OnItemSelectedListener{

String[] students = {"Mahi", "Bipin", "Sagar", "Jignesh", "Ashish"};

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

Spinner spin = (Spinner) findViewById(R.id.spinner1);  

        spin.setOnItemSelectedListener(this);

        

        ArrayAdapter<?> a = new ArrayAdapter(this,android.R.layout.simple_spinner_item,students);  

        a.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

        

        spin.setAdapter(a);

}

@Override  

   public void onItemSelected(AdapterView<?> arg0, View arg1, int position,long id) {  

       Toast.makeText(getApplicationContext(),students[position] ,Toast.LENGTH_LONG).show();  

   }

@Override

public boolean onCreateOptionsMenu(Menu menu) {

// Inflate the menu; this adds items to the action bar if it is present.

getMenuInflater().inflate(R.menu.main, menu);

return true;

}

@Override

public void onNothingSelected(AdapterView<?> arg0) {

// TODO Auto-generated method stub

}

}

Output: