MainActivity.java

package net.sgoliver.android.notificaciones;

import android.os.Bundle;
import android.app.Activity;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.graphics.drawable.BitmapDrawable;
import android.support.v4.app.NotificationCompat;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity {
	
	private Button btnNotificacion; 
	
	private static final int NOTIF_ALERTA_ID = 1;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		btnNotificacion = (Button)findViewById(R.id.BtnNotif);
        
        btnNotificacion.setOnClickListener(new OnClickListener() {
			public void onClick(View v) {
				NotificationCompat.Builder mBuilder =
				        new NotificationCompat.Builder(MainActivity.this)
				        .setSmallIcon(android.R.drawable.stat_sys_warning)
				        .setLargeIcon((((BitmapDrawable)getResources()
				        		.getDrawable(R.drawable.ic_launcher)).getBitmap()))
				        .setContentTitle("Mensaje de Alerta")
				        .setContentText("Ejemplo de notificaci�n.")
				        .setContentInfo("4")
				        .setTicker("Alerta!");

				Intent notIntent = 
						new Intent(MainActivity.this, MainActivity.class);
				
				PendingIntent contIntent = PendingIntent.getActivity(
						MainActivity.this, 0, notIntent, 0);
				
				mBuilder.setContentIntent(contIntent);
				
				NotificationManager mNotificationManager =
				    (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);

				mNotificationManager.notify(NOTIF_ALERTA_ID, mBuilder.build());
			}
		});
	}

	@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;
	}

}