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CLLocation如何实现可均衡协议?

equatable cllocation swift ios

5

Duncan C · 技术社区 · 8 年前

在回答另一个问题时,我发现 CLLocation 类符合 Equatable

lat/long的精确匹配?纬度/经度和海拔的精确匹配?纬度、经度、海拔和时间戳是否完全匹配?速度和航向呢?那么...怎么样 CL位置 仅使用横向/纵向对创建的对象?位置的各种其他值不是可选值,因此使用 init(latitude:longitude:)

3 回复 | 直到 8 年前

1

2

mfaani 8 年前

import Foundation
import UIKit
import CoreLocation

class ViewController: UIViewController{

    var cl1 = CLLocation()
    var cl2 = CLLocation()

    override func viewDidLoad() {
        super.viewDidLoad()
        if cl1 == cl2{

        }
    }
}

然后我点击命令 == (来自 if cl1 == cl2 ). 这让我想到:

extension NSObject : CVarArg {
}

public func ==(lhs: Selector, rhs: Selector) -> Bool

public func ==(lhs: NSObject, rhs: NSObject) -> Bool

public struct NSZone {
}

CLLocation 然后看到:

open class CLLocation : NSObject, NSCopying, NSSecureCoding {
...
}

所以基本上 == NSObject 它只比较引用。

2

JAL 8 年前

怎么做 CLLocation

没有。没有被覆盖的 == CL位置 实例。呼叫时 CL位置 NSObject ==

public func ==(lhs: NSObject, rhs: NSObject) -> Bool

实例中,要么比较您关心的每个属性(纬度或经度),要么使用内置 distance(from:) 方法,并将其与 CLLocationDistance 门槛

3

0

sfbarry14 8 年前

CLLocation类与任何符合Equatable的类一样,实现了(=)运算符

import UIKit
import CoreLocation

var str = "Hello, playground"

var coordinate = CLLocationCoordinate2D.init(latitude: 42.0, longitude: 42.0)
var accuracy = CLLocationAccuracy.init(24.0)
var date = Date.init(timeIntervalSinceNow: 0)

var loc1 = CLLocation.init(coordinate: coordinate, altitude: 44.0, horizontalAccuracy: accuracy, verticalAccuracy: accuracy, timestamp: date)
var loc2 = CLLocation.init(coordinate: coordinate, altitude: 44.0, horizontalAccuracy: accuracy, verticalAccuracy: accuracy, timestamp: date)
var loc3 = CLLocation.init(latitude: 42.0, longitude: 42.0)
var loc4 = CLLocation.init(latitude: 42.0, longitude: 42.0)
var loc5 = CLLocation.init(coordinate: coordinate, altitude: 44.0, horizontalAccuracy: accuracy, verticalAccuracy: accuracy, course: .infinity, speed: 55.0, timestamp: date)
var loc6 = CLLocation.init(coordinate: coordinate, altitude: 44.0, horizontalAccuracy: accuracy, verticalAccuracy: accuracy, course: .infinity, speed: 55.0, timestamp: date)

var bool1 = loc1 == loc2  //false
var bool2 = loc2 == loc3  //false
var bool3 = loc2 == loc2  //true
var bool4 = loc1 == loc4  //false
var bool5 = loc5 == loc6  //false

唯一的布尔值是bool3。

因此,无论不同CLLocation对象上的单个属性是否相同,==运算符都不会将对象视为相等。我猜比较位置的最好方法是比较你感兴趣的CLLocation对象的字段