打开路线功能无法以编程方式打开苹果地图

Question

I am working on a project right now and am stuck on the final part. I have designed an app with 20 custom annotations to be used by our wedding guests to find nearby restaurants, bars, coffee shops, etc. There are various custom annotation to identify what each location is. It also asks for users current location so they can find things nearby. I would like to be able to click on the annotations and have our friends and family be able to get directions from their current location to the annotation. It seems like the best way to do this is by opening up the apple maps app with my latitude and longitude coordinates in my custom point annotations. My code though does not seem to open that maps app at all. I have added a right call out, I have looked through every since question old and new asking about this and can not find a solution. Any advice will be much appreciated as this is my first real swift app. Below is my current open directions function. Thank you in advance for any help or insight.

    func openDirections(_ address :String?) {

    self.geocoder.geocodeAddressString(address!, completionHandler: { (placemarks :[CLPlacemark]?, error :NSError?) -> Void in

        let placemark = placemarks![0] as CLPlacemark

        let destinationPlacemark = MKPlacemark(coordinate: placemark.location!.coordinate, addressDictionary: placemark.addressDictionary as? [String:NSObject])

        let mapItem = MKMapItem(placemark: MKPlacemark(coordinate: placemark.location!.coordinate, addressDictionary:nil))
        mapItem.openInMaps(launchOptions: [MKLaunchOptionsDirectionsModeKey : MKLaunchOptionsDirectionsModeDriving])

        let startingMapItem = MKMapItem.forCurrentLocation()
        let destinationMapItem = MKMapItem(placemark: destinationPlacemark)

        let directionsRequest = MKDirectionsRequest()
        directionsRequest.transportType = .automobile
        directionsRequest.source = startingMapItem
        directionsRequest.destination = destinationMapItem

        let directions = MKDirections(request: directionsRequest)

        directions.calculate(completionHandler: { (response :MKDirectionsResponse?, error :NSError?) -> Void in

            let route = response!.routes[0] as MKRoute

            if route.steps.count > 0 {

                for step in route.steps {

                    print(step.instructions)

                }
            }

            self.mapView!.add((route.polyline), level: MKOverlayLevel.aboveRoads)
            } as! MKDirectionsHandler)
        } as! CLGeocodeCompletionHandler)
}

Answer 1

Go ahead and delete everything you wrote and do some research on how to write a new, better, cleaner function. Here is what worked for me and I hope it helps someone else.

    func mapView(_ mapView: MKMapView, annotationView view:MKAnnotationView, calloutAccessoryControlTapped control: UIControl) {

    let placemark = MKPlacemark(coordinate: view.annotation!.coordinate, addressDictionary: nil)
    let mapItem = MKMapItem(placemark: placemark)
    let launchOptions = [MKLaunchOptionsDirectionsModeKey:MKLaunchOptionsDirectionsModeTransit]
    self.title = title
    mapItem.name = title
    mapItem.openInMaps(launchOptions: launchOptions)
}