Notification中如何传值给上一个Activity

notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);                    Notification notification = new Notification(                            android.R.drawable.stat_notify_chat, "Hello",                            System.currentTimeMillis());                    Intent notificationIntent = new Intent(MyNotification.this,                            SendActivity.class);                    System.out.println("xy="+xy);                                            notificationIntent.putExtra("xy", xy);                                        PendingIntent pIntent = PendingIntent.getActivity(                            MyNotification.this, 0, notificationIntent, 0);                    notification.setLatestEventInfo(MyNotification.this,                            contentTitle, contentText + "**" + str, pIntent);                    System.out.println("Handler  id=" + MyNotification.ID);                    notificationManager.notify(MyNotification.ID, notification);