android - Resume an activity when clicked on a notification

Question

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.

Here is the code used to create the pendingintent:

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());

Answer 1

You need to set flags in your PendingIntent's ...like FLAG_UPDATE_CURRENT.

Here is all on it. http://developer.android.com/reference/android/app/PendingIntent.html

Edit 1: I misunderstood the question.

Here are links to topics that had the same issue but are resolved:

resuming an activity from a notification

Notification Resume Activity

Intent to resume a previously paused activity (Called from a Notification)

Android: resume app from previous position

Please read the above answers for a full solution and let me know if it works.