Adding String array resource data to the Spinner

First Create a layout in the res/layout folder, (main.xml)
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@drawable/treeimage"
    >
    <TextView 
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello"
        android:layout_marginLeft="80dp"
        android:layout_marginTop="20dp"
        android:textSize="25sp"
        android:textColor="#CCCCCC"
        />
    <Spinner android:id="@+id/Spinner01"
            android:layout_width="300dp"
            android:layout_height="50dp"
            android:prompt="@string/Convertion"
            android:layout_marginTop="20dp"
            android:layout_marginLeft="10dp"
            />
 
</LinearLayout>

Run the application, it will display the page like below, A Spinner will be added in the layout.

After that Add your Array values in the string.xml, available in the res/values folder.

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="hello">Convertion List</string>
    <string name="app_name">DCConvertion</string>
   
    <string name="Convertion">Select Convertion</string>
   
    <string-array name="Convertion_Element">
        <item>(Select)</item>
        <item>Dollar To Currency</item>
        <item>Currency To Dollar</item>
    </string-array>
   
    <string name="title">Dollar To Currency</string>
    <string name="titlecur">Currency To Dollar</string>
    <string name="dollar">Dollar Value</string>
    <string name="currency">Currency Value</string>
    <string name="convert">Convert</string>
   
</resources>

The above bolded item is the array element that are going to load in the spinner. You can add as many item you needed inside the <item></item> tag.

After that, Create a class file called DCConvertion.java

package com.convertion.dc;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.Toast;
import android.widget.AdapterView.OnItemSelectedListener;

public class DCConvertion extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.main);
      //  con=getApplicationContext();
        Spinner spinner=(Spinner)findViewById(R.id.Spinner01);
        ArrayAdapter<CharSequence> adapter=ArrayAdapter.createFromResource(this, R.array.Convertion_Element, android.R.layout.simple_spinner_item);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinner.setAdapter(adapter);
        spinner.setOnItemSelectedListener(new OnItemSelectedListener(){

            public void onItemSelected(AdapterView<?> parent, View view, int pos,long id)
            {
                // TODO Auto-generated method stub
                //Toast.makeText(parent.getContext(), "Selected : "+parent.getItemIdAtPosition(pos), Toast.LENGTH_LONG).show();
                switch(pos)
                {
                    case 0:
                        Toast.makeText(parent.getContext(), "Please Select Your Choice", Toast.LENGTH_LONG).show();
                        break;
                       
                    case 1:
                        Toast.makeText(parent.getContext(), "You are Selected Doller to Currency Convertion", Toast.LENGTH_LONG).show();
                        Intent indtoc=new Intent(DCConvertion.this,Dollartocurrencyconvert.class);
                        startActivity(indtoc);
                        break;
                       
                    case 2:
                        Toast.makeText(parent.getContext(), "You are Selected Currency to Dollar Convertion", Toast.LENGTH_LONG).show();
                        Intent inctod=new Intent(DCConvertion.this,Currencytodollarconvert.class);
                        startActivity(inctod);
                        break;
                }
            }

            public void onNothingSelected(AdapterView<?> arg0)
            {
                // TODO Auto-generated method stub
               
            }
           
            });
    }
}


The above bolded code will create an array adapter for the spinner, inside the array adapter you should load your string array resource R.id.Convertion_Element. Finally set the loaded adapter to the spinner.

Run the program, and click the spinner, it will display like above image.