CLLocationDistance转换

Question

我是一名有用的助手，可以为您翻译文本。

我有一个类型为CLLocationDistance的变量中存储了距离，我需要将它转换为整数变量，该如何做？

我已经使用了：

CLLocationDistance kilometers;

int distance = [kilometers intValue];

但是它出现了错误。

求助大家

- Manish Jain

---

你收到的错误信息可能会对其他人有所帮助，请将其包含在内。 - KevinDTimm

Answer 1

https://developer.apple.com/library/mac/#documentation/CoreLocation/Reference/CLLocation_Class/CLLocation/CLLocation.html

distanceFromLocation:

返回接收器位置到指定位置的距离（以米为单位）。

- (CLLocationDistance)distanceFromLocation:(const CLLocation *)location

参数

location：另外一个位置。

返回值 两个位置之间的距离（以米为单位）。

返回类型是double而不是int。它也不是一个NSNumber。

- 0x8badf00d

---

澄清一下，由于它是一个Double（一种内置类型，而不是对象），因此没有[intValue]方法可运行。既然你愿意失去精度，只需分配该值即可。如果您想四舍五入，请添加0.5，然后再分配它。 - KevinDTimm

Answer 2

iOS 10推出了一个新的Measurement类，可以轻松地进行距离转换。

这里有一个扩展函数用于进行距离转换：

extension Double {
  func convert(from originalUnit: UnitLength, to convertedUnit: UnitLength) -> Double {
    return Measurement(value: self, unit: originalUnit).converted(to: convertedUnit).value
  }
}

例子用法：

let miles = 1.0
let metersInAMile = miles.convert(from: .miles, to: .meters)

let mileInFeet = 5280.0
let feetInAMile = mileInFeet.convert(from: .feet, to: .miles)

let marathonInFeet = 138_435.0
let milesInMarathon = marathonInFeet.convert(from: .feet, to: .miles)
let kmInMarathon = marathonInFeet.convert(from: .feet, to: .kilometers)

let inch = 1.0
let centimetersInInch = inch.convert(from: .inches, to: .centimeters)

- Adrian

Answer 3

使用CLLocationDistance可以计算两个位置之间的距离，默认以米为单位。若要转换为千米，请将CLLocationDistance/1000.0相除。若要得到英里，请将CLLocationDistance*0.62137相乘。

 //Pass your current location Latitude and longitude
                     CLLocation *currentlocation = [[CLLocation alloc] initWithLatitude:13.015370f  longitude:80.200393f];
 //Pass your destination location Latitude and longitude 
CLLocation *destination = [[CLLocation alloc] initWithLatitude:37.420948f longitude:-122.09578499999998f];
CLLocationDistance meters = [currentlocation distanceFromLocation:destination];
//get distance in meters
    NSLog(@"meters :%f", meters);
//get distance in kilometers
    CLLocationDistance kilometers = meters / 1000.0;
    NSLog(@"kilometers :%f", kilometers);
//Get distance in miles
    NSLog(@"Miles:%f",kilometers*0.62137);
//convert kilometers to int value
    int num=kilometers;

- Kamalkumar.E

---

请添加解释以改善答案；仅有代码的答案是不被鼓励的！谢谢！ - namezero

使用CLLocationDistance计算两个纬度和经度之间的距离，默认情况下它以米为单位给出值。要转换为千米，请将CLLocationDistance除以1000.0。要获取英里，请将CLLocationDistance乘以0.62137。 - Kamalkumar.E

Answer 4

SWIFT 4

虽然来晚了一步，但您也可以创建如下的扩展：

CLLocationDistance.swift

import UIKit
import CoreLocation

extension CLLocationDistance {
    func inMiles() -> CLLocationDistance {
        return self*0.00062137
    }

    func inKilometers() -> CLLocationDistance {
        return self/1000
    }
}

您可以这样称呼它：

distance.inKilometers()

我希望这能对任何在此遇到问题的人有所帮助！

- Jeremie

Answer 5

Swift:

  var initialLocation :CLLocation?
  var updatedUserLocation :CLLocation?
  var distanceBetweenLocations: CLLocationDistance?

//MK MapView Delegate
  func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {

    updatedUserLocation = locations.last
    distanceBetweenLocations =  updatedUserLocation!.distanceFromLocation(initialLocation!)

    //convert To Miles
    distanceBetweenLocations = Utility.convertCLLocationDistanceToMiles(distanceBetweenLocations)

//Setting Distance Value
    distanceLabel.text = String(format: " Distance : %.2f ", distanceBetweenLocations!)

  }

注意：我有一个名为Utility的类，它提供了项目中通用的类方法。这是为了更好地重用代码并减少冗余。

//  Utility.swift

import UIKit
import Foundation
import CoreLocation

class Utility {

  class func convertCLLocationDistanceToMiles (var targetDistance : CLLocationDistance?) -> CLLocationDistance {
    targetDistance =  targetDistance!*0.00062137
    return targetDistance!
  }
  class func convertCLLocationDistanceToKiloMeters (var targetDistance : CLLocationDistance?) -> CLLocationDistance {
    targetDistance =  targetDistance!/1000
    return targetDistance!
  }

}

- Alvin George

Answer 6

用Swift编程就容易多了：

// Use you CLLocationDistance as the value 'kilometers':    
let kms = Measurement(value: kilometers, unit: UnitLength.kilometers)
// Then you can convert that to miles if you'd like:
let miles = kms.converted(to: .miles)
// Get the double value:
let doubleValue = miles.value
print("The distances is \(doubleValue) miles")

- Joshua Hart