title: Resume an activity when clicked on a notification
body: <p>I've made an app which manage sms, I've created the notifications but when I click on them it starts another activity, I would like to know how to check if an activity has been stopped and resume it.</p>
  
  <p>Here is the code used to create the pendingintent:</p>
  
  <pre><code>private void createNotification(SmsMessage sms, Context context){
  
      final NotificationManager nm = (NotificationManager)context.getSystemService(Context.NOTIFICATION_SERVICE);
  
      String contentTitle = "";
  
  
      // construct the Notification object.
          final NotificationCompat.Builder  builder = new NotificationCompat.Builder(context)
          .setContentTitle(contentTitle)
           .setContentText(sms.getMessageBody())
           .setSmallIcon(R.drawable.ic_launcher)
           .setLargeIcon(getIconBitmap())
           .setNumber(nmessages);
  
          builder.setAutoCancel(true);
  
          //(R.drawable.stat_sample, tickerText,
            //      System.currentTimeMillis());
  
          // Set the info for the views that show in the notification panel.
          //notif.setLatestEventInfo(this, from, message, contentIntent);
          /*
          // On tablets, the ticker shows the sender, the first line of the message,
          // the photo of the person and the app icon.  For our sample, we just show
          // the same icon twice.  If there is no sender, just pass an array of 1 Bitmap.
          notif.tickerTitle = from;
          notif.tickerSubtitle = message;
          notif.tickerIcons = new Bitmap[2];
          notif.tickerIcons[0] = getIconBitmap();;
          notif.tickerIcons[1] = getIconBitmap();;
          */
  
       // Creates an explicit intent for an Activity in your app
          Intent resultIntent = new Intent(context, BasicActivity.class);
  
          resultIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
          // Because clicking the notification opens a new ("special") activity, there's
          // no need to create an artificial back stack.
          PendingIntent resultPendingIntent =
              PendingIntent.getActivity(
              context,
              0,
              resultIntent,
              PendingIntent.FLAG_UPDATE_CURRENT
          );
  
  
         // Ritardo in millisecondi
  
  
  
       builder.setContentIntent(resultPendingIntent);
  
       nm.notify(R.drawable.ic_drawer, builder.build());
  </code></pre>