can't figure out how to embed my current location in message body correctly using CLPlacemark

问题

I had hardly tried few days ago to embed my current location in Message body on my iPhone, but I failed.

I tried all I have in my mind, but I only got errors

Last error I got is

"fatal error: unexpectedly found nil while unwrapping an Optional value"

I created an object of CLPlacemark and I made it optional, which means it could have value or could have nil.

is there any way to create a message with my current location ?

MainMenu file

import UIKit
import Social
import MessageUI
import Foundation
import CoreLocation


class MainMenu: UIViewController , MFMessageComposeViewControllerDelegate , UINavigationControllerDelegate , MFMailComposeViewControllerDelegate, CLLocationManagerDelegate {

    let locationManager = CLLocationManager()

    func messageComposeViewController(controller: MFMessageComposeViewController, didFinishWithResult result: MessageComposeResult) {
    }

    let placeMarks = Location()

    @IBAction func TapOnEmergency(sender: UIButton) {

       let textMessageRecipients = ["+123456789"]

       let messageComposer = MFMessageComposeViewController()

       let Emergency  = UIAlertController(title: "Do You Need Help ?", message: nil, preferredStyle: UIAlertControllerStyle.ActionSheet)

       let Yes = UIAlertAction(title: "YES", style: .Default) { (action) in

            if (MFMessageComposeViewController.canSendText()) {

                messageComposer.messageComposeDelegate = self
                messageComposer.recipients = textMessageRecipients

                messageComposer.body = "I'm Lost, I need some Help, Here's my Location \(self.placeMarks.currentLocation!.country)"

                self.navigationController?.presentViewController(messageComposer, animated: true){}
                self.presentViewController(messageComposer, animated: true, completion: nil)
                self.messageComposeViewController(messageComposer, didFinishWithResult: MessageComposeResultCancelled)



            } else {

                let errorAlert = UIAlertController(title: "Cannot Send Text Message", message: "Your device is not able to send text messages.", preferredStyle: UIAlertControllerStyle.Alert)

                            errorAlert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.Cancel, handler: nil))

                            self.presentViewController(errorAlert, animated: true, completion: nil)

            }



            let Options  = UIAlertController(title: "Do You Want to Call Your Supervisor ?", message: nil, preferredStyle: UIAlertControllerStyle.ActionSheet)

            let dialNumber = UIAlertAction(title: "YES", style: .Default) { (action) in

            let call:NSURL = NSURL(string: "tel://123456789")!
            UIApplication.sharedApplication().openURL(call)

            }

            Options.addAction(dialNumber)

            let Dismiss = UIAlertAction(title: "Dismiss", style: .Destructive) { (action) in

            }

            Options.addAction(Dismiss)


            self.presentViewController(Options, animated: true) {}


        }

        Emergency.addAction(Yes)

        let No = UIAlertAction(title: "Dismiss", style: .Destructive) { (action) in

        }

        Emergency.addAction(No)

        self.presentViewController(Emergency, animated: true) {}

    }
}

Location file

import UIKit
import CoreLocation

class Location: UIViewController, CLLocationManagerDelegate {

    let locationManager = CLLocationManager()
    var currentLocation : CLPlacemark?
}

回答1:

Just creating CLPlacemark will not fetch location for you. You will have to create object of CLLocationManager and then update your current location using startUpdatingLocation method of CLLocationManager object. Also you'll have to implement delegate methods for receiving the current location this way.

import UIKit
import CoreLocation

class Location: UIViewController, CLLocationManagerDelegate {

    let locationManager = CLLocationManager()
    var currentLocation : CLPlacemark?
    var locationManager = CLLocationManager()

    private override init() {
        super.init()
        locationManager.delegate = self
    }
    func updateLocation()
    {
        locationManager.startUpdatingLocation()
    }
    func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
        locationManager.stopUpdatingLocation()
        let location  : CLLocation = locations.last as CLLocation!
        //use reverse geocoding to get the address from location coordinates you got
    }

}

Once you get location coordinates you can do reverse geocoding to get the place mark or exact address. Refer to Reverse Geocode Location in Swift for reverse geocoding. Regarding the error you are getting, you can check if place mark object is nil before creating a message.

来源：https://stackoverflow.com/questions/33502130/cant-figure-out-how-to-embed-my-current-location-in-message-body-correctly-usin

标签

ios

swift

swift2

ios9

clplacemark