Android: How to resume an App from a Notification?

I am trying to program my notification to RESUME my app, instead of simply starting a new instance of my app... I am basically looking for it to do the same thing as when the Home button is long-pressed and the app is resumed from there.

Here is what I am currently doing:

void notifyme(String string){

    String ns = Context.NOTIFICATION_SERVICE;
    NotificationManager mNotificationManager = (NotificationManager)
                                                getSystemService(ns);

    int icon = R.drawable.notification_icon;        // icon from resources
    CharSequence tickerText = string + " Program Running...";     // ticker-text
    long when = System.currentTimeMillis();         // notification time
    Context context = getApplicationContext()开发者_如何转开发;      // application Context
    CharSequence contentTitle = *********;  // expanded message title
    CharSequence contentText = string + " Program Running...";//expanded msg text

    Intent notificationIntent = new Intent(this, Main.class);
    PendingIntent contentIntent = PendingIntent.getActivity(
                                                this, 0, notificationIntent, 0);

    // the next two lines initialize the Notification, using the configurations
    // above
    Notification notification = new Notification(icon, tickerText, when);
    notification.setLatestEventInfo(context, contentTitle, contentText,
                                                                contentIntent);
    final int HELLO_ID = 1;
    mNotificationManager.notify(HELLO_ID, notification);
}

I am guessing that the new Intent line is where the problem lies... any help would be appreciated!

you need to set your flags

 notification.flags = Notification.FLAG_ONGOING_EVENT | Notification.FLAG_NO_CLEAR;   
 notificationIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);

Also, if you never ever want there to be a duplicate activity give it this attribute in the manifest

android:launchMode="singleTask"