从用户位置查找数组中最接近的经度和纬度 - iOS Swift

Question

在这里发布的问题中,用户问:

我有一个充满经度和纬度的阵列.我的用户位置有两个双变量.我想测试用户位置与阵列之间的距离,以查看最接近的位置.我该怎么做呢？

这将获得2个位置之间的距离,但是要了解我如何针对一系列位置进行测试.

作为回应,他得到了以下代码:

NSArray *locations = //your array of CLLocation objects
CLLocation *currentLocation = //current device Location

CLLocation *closestLocation;
CLLocationDistance smallestDistance = DBL_MAX; // set the max value

for (CLLocation *location in locations) {
    CLLocationDistance distance = [currentLocation  distanceFromLocation:location];

    if (distance < smallestDistance) {
        smallestDistance = distance;
        closestLocation = location;
    }
}
NSLog(@"smallestDistance = %f", smallestDistance);

我在我正在处理的应用程序中遇到完全相同的问题,我认为这段代码可以完美地运行.但是,我正在使用Swift,此代码在Objective-C中.

我唯一的问题是:它应该如何看待Swift？

谢谢你的帮助.我是所有这一切的新手,看到Swift中的这段代码可能是一个很大的问题.

Answer 1

对于Swift 3,我创建了一小段"功能"代码:

let coord1 = CLLocation(latitude: 52.12345, longitude: 13.54321)
let coord2 = CLLocation(latitude: 52.45678, longitude: 13.98765)
let coord3 = CLLocation(latitude: 53.45678, longitude: 13.54455)

let coordinates = [coord1, coord2, coord3]

let userLocation = CLLocation(latitude: 52.23678, longitude: 13.55555)

let closest = coordinates.min(by: 
{ $0.distance(from: userLocation) < $1.distance(from: userLocation) })

Answer 2

var closestLocation: CLLocation?
var smallestDistance: CLLocationDistance?

for location in locations {
  let distance = currentLocation.distanceFromLocation(location)
  if smallestDistance == nil || distance < smallestDistance {
    closestLocation = location
    smallestDistance = distance
  }
}

print("smallestDistance = \(smallestDistance)")

或作为一种功能:

func locationInLocations(locations: [CLLocation], closestToLocation location: CLLocation) -> CLLocation? {
  if locations.count == 0 {
    return nil
  }

  var closestLocation: CLLocation?
  var smallestDistance: CLLocationDistance?

  for location in locations {
    let distance = location.distanceFromLocation(location)
    if smallestDistance == nil || distance < smallestDistance {
      closestLocation = location
      smallestDistance = distance
    }
  }

  print("closestLocation: \(closestLocation), distance: \(smallestDistance)")
  return closestLocation
}