import android.app.Activity; 
import android.os.Bundle; 
import android.view.Window; 
import android.view.WindowManager; 
 
public class ActivityName extends Activity { 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState); 
        // remove title 
        requestWindowFeature(Window.FEATURE_NO_TITLE); 
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, 
            WindowManager.LayoutParams.FLAG_FULLSCREEN); 
        setContentView(R.layout.main); 
    } 
} 
<activity android:name=".ActivityName" 
    android:label="@string/app_name" 
    android:theme="@android:style/Theme.Black.NoTitleBar.Fullscreen"> 
</activity> 

import android.app.Activity;
import android.os.Bundle;
import android.view.Gravity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.SubMenu;
import android.widget.Toast;

/**
 * Class which shows how to work with Submenus
 *
 * @author FaYnaSoft Labs
 */
public class Main extends Activity {

	private static final int FILE = 0;
	private static final int EDIT = 1;

	private static final int NEW_MENU_ITEM = Menu.FIRST;
	private static final int SAVE_MENU_ITEM = NEW_MENU_ITEM + 1;

	private static final int UNDO_MENU_ITEM = SAVE_MENU_ITEM + 1;
	private static final int REDO_MENU_ITEM = UNDO_MENU_ITEM + 1;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		SubMenu fileMenu = menu.addSubMenu("File");
		SubMenu editMenu = menu.addSubMenu("Edit");
		fileMenu.add(FILE, NEW_MENU_ITEM, 0, "new");
		fileMenu.add(FILE, SAVE_MENU_ITEM, 1, "save");
		editMenu.add(EDIT, UNDO_MENU_ITEM, 0, "undo");
		editMenu.add(EDIT, REDO_MENU_ITEM, 1, "redo");
		return super.onCreateOptionsMenu(menu);
	}

	@Override
	public boolean onOptionsItemSelected(MenuItem item) {
		switch (item.getItemId()) {
		case NEW_MENU_ITEM:
			showMsg("New");
			break;
		case SAVE_MENU_ITEM:
			showMsg("Save");
			break;
		case UNDO_MENU_ITEM:
			showMsg("Undo");
			break;
		case REDO_MENU_ITEM:
			showMsg("Redo");
			break;
		}
		return super.onOptionsItemSelected(item);
	}

	private void showMsg(String message) {
		Toast msg = Toast.makeText(Main.this, message, Toast.LENGTH_LONG);
		msg.setGravity(Gravity.CENTER, msg.getXOffset() / 2,
				msg.getYOffset() / 2);
		msg.show();
	}
}

  menu.add(0, ADD_MENU_ITEM, 0, "Add").setIcon(android.R.drawable.ic_menu_add);

menu.add(0, NEW_MENU_ITEM, 0, "New").setAlphabeticShortcut('N');