Android : Fragment doesn't open on clicking on Notification

Question

I have same problem as many but doesn't seems to find solution by their answers, so I have to write my own..

I have a notification from which I would like to open a fragment by clicking on it but it doesn't open WHY?

here is my code

 public void showStatusNotification() {

    Intent resultIntent = new Intent(this, MainActivity.class);
    resultIntent.setAction("OpenStatusFragment");

    PendingIntent resultPendingIntent =
            PendingIntent.getActivity(
                    this,
                    0,
                    resultIntent,
                    PendingIntent.FLAG_UPDATE_CURRENT
            );

    NotificationCompat.Builder mBuilder =
            new NotificationCompat.Builder(this)
                    .setSmallIcon(R.mipmap.dc_feedback)
                    .setAutoCancel(true)
                    .setContentTitle("Order Id DC256649")
                    .setContentIntent(resultPendingIntent)
                    .setContentText("Your Order has been cancelled as per your request");


    //mBuilder.setContentIntent(resultPendingIntent);

    NotificationManager mNotifyMgr =
            (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
    mNotifyMgr.notify(mNotificationId2, mBuilder.build());
    Log.v("notification","Notification");
}

I am defining this code in MainActivity.java only

In onCreate method I am opening fragment like

final android.support.v4.app.FragmentManager fragmentManager = getSupportFragmentManager();
    if(getIntent().getAction().equals("OpenNotificationFragment")) {
        fragmentManager.beginTransaction()
                .replace(R.id.fragment_main_container, new NotificationFragment()).addToBackStack(PastOrderFragment.TAG)
                .commitAllowingStateLoss();
        mDrawerLayout.closeDrawer(mDrawerList);
    }
    else {
        fragmentManager.beginTransaction()
                .replace(R.id.fragment_main_container, new OrderStatusFragment()).addToBackStack(PastOrderFragment.TAG)
                .commitAllowingStateLoss();
        mDrawerLayout.closeDrawer(mDrawerList);
    }