如何設置UITabBar背景圖像更改？

Question

我如何基於與當前位置的距離對數組進行排序並在tableview中顯示。當我使用排序時，沒有得到任何適當的結果，我獲得了具有隨機距離的數組。任何人都可以指導我解決這個問題

Answer 1

根據與當前位置的距離以最佳方式對位置進行排序，將具有結構形式的位置點

struct LocationPoints {
    var latitude: CLLocationDegrees
    var longitude: CLLocationDegrees

    func distance(to currentLocation: CLLocation) -> CLLocationDistance {
        return CLLocation(latitude: self.latitude, longitude: self.longitude).distance(from: currentLocation)
    }
}

假設您有一個具有經度和緯度的LocationPoints數組

var coordinates: [LocationPoints] = []
            coordinates.append(LocationPoints(latitude: Double(25), longitude: Double(24)))
                coordinates.append( LocationPoints(latitude: Double(23), longitude: Double(22)))

排序功能

    coordinates = sortLocationsWithCurrentLocation(locations: coordinates, currentLocation: CLLocation(latitude: Double(20), longitude: Double(21)))




    func sortLocationsWithCurrentLocation(locations:[LocationPoints],currentLocation:CLLocation) -> [LocationPoints] {
//set here current position as current location
            let currentPosition : CLLocation = CLLocation(latitude: 30, longitude: 24)
            let sortedLocations = locations.sorted(by: { (point1 : LocationPoints, point2 :LocationPoints) -> Bool in
                if point1.distance(to: currentPosition) < point2.distance(to: currentPosition)
                {
                    return true
                }
               return false
            })
            return sortedLocations
        }