<LinearLayout 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:orientation="vertical" 
 > 
 <EditText  
  android:id="@+id/etText" 
  android:layout_width="fill_parent" 
  android:layout_height="wrap_content" 
  android:hint="Enter text" 
  /> 
 <Button  
  android:id="@+id/bAdd" 
  android:layout_width="wrap_content" 
  android:layout_height="wrap_content" 
   android:text="Add"  
  /> 
 <ListView  
  android:id="@+id/listDisplay" 
  android:layout_width="fill_parent" 
  android:layout_height="wrap_content" 
  > 
 </ListView> 
 </LinearLayout>   

 import java.util.ArrayList; 
 import android.os.Bundle; 
 import android.app.Activity; 
 import android.view.Menu; 
 import android.view.View; 
 import android.view.View.OnClickListener; 
 import android.widget.ArrayAdapter; 
 import android.widget.Button; 
 import android.widget.EditText; 
 import android.widget.ListView; 
 public class MainActivity extends Activity implements OnClickListener { 
   Button b1; 
   ListView list; 
   EditText et; 
   private ArrayAdapter<String> adapter; 
   private ArrayList<String> items; 
   @Override 
   protected void onCreate(Bundle savedInstanceState) { 
      super.onCreate(savedInstanceState); 
      setContentView(R.layout.activity_main);//referencing UI 
      b1=(Button) findViewById(R.id.bAdd); //referencing button 
      list=(ListView) findViewById(R.id.listDisplay); //referencing listview 
      et=(EditText) findViewById(R.id.etText); //referencing edittext 
      b1.setOnClickListener(this); //adding click event to button 
      items=new ArrayList<String>(); 
      adapter=new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,items); 
      //Adapter used to bind array to the listview 
      list.setAdapter(adapter);//applying adapter to listview 
   } 
   @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 onClick(View v) { 
      // TODO Auto-generated method stub 
      switch(v.getId()){ 
      case R.id.bAdd: 
        items.add(0, et.getText().toString());//getting data from edittext 
        adapter.notifyDataSetChanged();//refereshes the adapter (listview) 
        et.setText(""); 
        break; 
      } 
   } 
 }