ทํา dropdownlist บน แอนดรอยด์ (android) ใช้ widgets ตัวไหนครับ

package com.myapp;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.TextView;
import android.widget.Spinner;
import android.widget.Toast;
import android.widget.ArrayAdapter;
import android.widget.AdapterView;
import java.util.ArrayList;
import java.util.List;

public class MainActivity extends Activity {
	

	List<String> arrList = new ArrayList<String>();
	TextView txtView1;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
	
		// spinner1
		Spinner spin = (Spinner) findViewById(R.id.spinner1); 
       
		arrList.add("Mercury");
		arrList.add("Venus");
		arrList.add("Earth");
		arrList.add("Mars");
	
		ArrayAdapter<String> arrAd = new ArrayAdapter<String>(MainActivity.this,
				android.R.layout.simple_spinner_item, 
				arrList);
        
		spin.setAdapter(arrAd);
		
		spin.setOnItemSelectedListener(new  AdapterView.OnItemSelectedListener() { 

              public void onItemSelected(AdapterView<?> adapterView, 
            	View view, int i, long l) { 
            	// TODO Auto-generated method stub
      				Toast.makeText(MainActivity.this,
           				String.valueOf("Your Selected : " + arrList.get(i)),
           					Toast.LENGTH_SHORT).show();
             
              	}

				public void onNothingSelected(AdapterView<?> arg0) {
					// TODO Auto-generated method stub
      				Toast.makeText(MainActivity.this,
               				String.valueOf("Your Selected Empty"),
               					Toast.LENGTH_SHORT).show();
				} 

        });

               
    }
    

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }
    
}