MKMapView MKPointAnnotation tap event not called

I am using a MKMapView (delegate is set correctly) with a MKPointAnnotation. The annotations are generated in this method called on a background thread.

func updateMapAnnotations() {
    for var i = 0; i < DataManager.getStationList().count; i++ {
        var s = DataManager.getStationList()[i] as Station
        var annotation = MKPointAnnotation()
        annotation.setCoordinate(CLLocationCoordinate2D(latitude: s.latitude, longitude: s.longitude))
        annotation.title = "\(s.id)"
        dispatch_async(dispatch_get_main_queue(), {
            self.mapView.addAnnotation(annotation)
        })
    }
}

The annotationViews are generated in here:

func mapView(mapView: MKMapView!, viewForAnnotation annotation: MKAnnotation!) -> MKAnnotationView! {
    if (annotation is MKUserLocation) {
        return nil
    }

    let reuseId = "StationAnnotation"

    let annoStation = DataManager.getStationById(annotation.title!.toInt()!)

    var anView = mapView.dequeueReusableAnnotationViewWithIdentifier(reuseId)
    if anView == nil {

        anView = MKAnnotationView(annotation: annotation, reuseIdentifier: reuseId)
        let base = UIView(frame: CGRect(x: 0, y: 0, width: 67, height: 26))

        let imageView = UIImageView(frame: CGRect(x: 2, y: 2, width: 22, height: 22))
        imageView.image = UIImage(named: "test")

        base.layer.cornerRadius = 3.0
        base.clipsToBounds = true
        base.backgroundColor = UIColor.whiteColor()

        var priceLabelBig = UILabel(frame: CGRect(x: 25, y: 0, width: 30, height: 25))
        priceLabelBig.textColor = UIColor.blackColor()
        priceLabelBig.font = UIFont(name: priceLabelBig.font.fontName, size: 15)

        var priceLabelSmall = UILabel(frame: CGRect(x: 55, y: 0, width: 12, height: 15))
        priceLabelSmall.textColor = UIColor.blackColor()
        priceLabelSmall.font = UIFont(name: priceLabelBig.font.fontName, size: 12)

        if let curPrice = annoStation?.getTextWithSettings().description {
        var stringLength = countElements(curPrice)
        var substringToIndex = stringLength - 1
            priceLabelBig.text = curPrice.substringToIndex(advance(curPrice.startIndex, substringToIndex))
            priceLabelSmall.text = curPrice.substringFromIndex(advance(curPrice.startIndex, substringToIndex))
        }

        base.addSubview(imageView)
        base.addSubview(priceLabelBig)
        base.addSubview(priceLabelSmall)

        anView.addSubview(base)
        anView.canShowCallout = true
    }
    else {
        anView.annotation = annotation
    }

    return anView
}

I know I have to set the annotations title and set 'canShowCallOut' to true to get the 'didSelectAnnotationView' working. As you can see, both is set correctly.

So what I have is a mapView (delegate is set), 'canShowCallOut' is true and a title is set and working.

To go on a detail-page, I want to track a tap on the annotationViews ('didSelectAnnotationView'), but it is not called.

What am I doing wrong?

Okay I found the solution by myself.

You have to set the annotationViews frame explicitly. If you just set subViews for the view, they will be shown, but the views frame is set to 0, 0 (height, weight). So you just can't tap it, cause the area is 0, 0 as well.

My solution is this, the interesting line is annotationView.frame = CGRect(x: 0, y: 0, width: 67, height: 26). Everything else is the same. Now a click on a annotation calls didSelectAnnotationView.

func mapView(mapView: MKMapView!, viewForAnnotation annotation: MKAnnotation!) -> MKAnnotationView! {
    if (annotation is MKUserLocation) {
        return nil
    }

    let reuseId = "stationAnnotation"

    let annoStation = DataManager.getStationById(annotation.title!.toInt()!)

    var annotationView = mapView.dequeueReusableAnnotationViewWithIdentifier(reuseId)
    if annotationView == nil {

        annotationView = MKAnnotationView(annotation: annotation, reuseIdentifier: reuseId)
        annotationView.frame = CGRect(x: 0, y: 0, width: 67, height: 26)
        let base = UIView(frame: CGRect(x: 0, y: 0, width: 67, height: 26))
        base.userInteractionEnabled = true

        let imageView = UIImageView(frame: CGRect(x: 2, y: 2, width: 22, height: 22))
        imageView.image = UIImage(named: "zapfsaeule")

        base.layer.cornerRadius = 3.0
        base.clipsToBounds = true
        base.backgroundColor = UIColor.whiteColor()

        var priceLabelBig = UILabel(frame: CGRect(x: 25, y: 0, width: 30, height: 25))
        priceLabelBig.textColor = UIColor.blackColor()
        priceLabelBig.font = UIFont(name: priceLabelBig.font.fontName, size: 15)

        var priceLabelSmall = UILabel(frame: CGRect(x: 55, y: 0, width: 12, height: 15))
        priceLabelSmall.textColor = UIColor.blackColor()
        priceLabelSmall.font = UIFont(name: priceLabelBig.font.fontName, size: 12)

        if let curPrice = annoStation?.getPriceWithSettings().description {
            var stringLength = countElements(curPrice)
            var substringToIndex = stringLength - 1
            priceLabelBig.text = curPrice.substringToIndex(advance(curPrice.startIndex, substringToIndex))
            priceLabelSmall.text = curPrice.substringFromIndex(advance(curPrice.startIndex, substringToIndex))
        }

        base.addSubview(imageView)
        base.addSubview(priceLabelBig)
        base.addSubview(priceLabelSmall)

        annotationView.addSubview(base)
        annotationView.annotation = annotation
    }
    else {
        annotationView.annotation = annotation
    }

    return annotationView
}