Question

我正致力于将城市（字符串）转换为坐标的功能。但是，当我调用函数时，我得到了＆＃34;（0.0,0.0）＆＃34;结果是。它应该是纬度和经度。

请帮帮我。谢谢！

这是功能

func getCoordinates(huidigeLocatie: String) -> (lat: CLLocationDegrees, long: CLLocationDegrees) {

    var lat:CLLocationDegrees
    var long:CLLocationDegrees

    var geocoderHuidigeLocatie = CLGeocoder()

    geocoderHuidigeLocatie.geocodeAddressString(huidigeLocatie, completionHandler:
        {(placemarks: [AnyObject]!, error: NSError!) in

            if error != nil {

                println("Geocode failed with error: \(error.localizedDescription)")

            } else if placemarks.count > 0 {

                let placemark = placemarks[0] as CLPlacemark
                let location = placemark.location

                var lat = location.coordinate.latitude
                var long = location.coordinate.longitude

            }
    })

    return (lat: CLLocationDegrees(), long: CLLocationDegrees())
}

Answer 1

这里有两个问题：

您想要返回实际的lat和long变量，而不是CLLocationDegrees()。
更微妙的问题是您正在调用异步返回其结果的函数，因此您无法立即返回值。相反，您可以使用自己的completionHandler模式。

例如：

func getCoordinates(huidigeLocatie: String, completionHandler: (lat: CLLocationDegrees!, long: CLLocationDegrees!, error: NSError?) -> ()) -> Void {

    var lat:CLLocationDegrees
    var long:CLLocationDegrees

    var geocoderHuidigeLocatie = CLGeocoder()

    geocoderHuidigeLocatie.geocodeAddressString(huidigeLocatie) { (placemarks: [AnyObject]!, error: NSError!) in

        if error != nil {

            println("Geocode failed with error: \(error.localizedDescription)")

            completionHandler(lat: nil, long: nil, error: error)

        } else if placemarks.count > 0 {

            let placemark = placemarks[0] as CLPlacemark
            let location = placemark.location

            let lat = location.coordinate.latitude
            let long = location.coordinate.longitude

            completionHandler(lat: lat, long: long, error: nil)
        }
    }
}

你会这样称呼它：

getCoordinates(string) { lat, long, error in
    if error != nil { 
        // handle the error here 
    } else {
        // use lat, long here
    }
}

// but not here

Answer 2

你应该return (lat: lat, long: long)。

iOS Swift坐标函数返回nil

2 个答案: