我编写了在文本字段中键入时显示城市名称的代码。我可以使用 For Each 循环显示搜索结果。我需要单击其中一个结果并获取城市名称的地理位置。现在我正在努力从该城市名称中获取地理位置(纬度、经度)。是否有解决方案可以将其实现到我的代码中?
class LocationService: NSObject, ObservableObject {
enum LocationStatus: Equatable {
case idle
case noResults
case isSearching
case error(String)
case result
}
@Published var queryFragment: String = ""
@Published private(set) var status: LocationStatus = .idle
@Published private(set) var searchResults: [MKLocalSearchCompletion] = []
private var queryCancellable: AnyCancellable?
private let searchCompleter: MKLocalSearchCompleter!
init(searchCompleter: MKLocalSearchCompleter = MKLocalSearchCompleter()) {
self.searchCompleter = searchCompleter
super.init()
self.searchCompleter.delegate = self
queryCancellable = $queryFragment
.receive(on: DispatchQueue.main)
// we're debouncing the search, because the search completer is rate limited.
// feel free to play with the proper value here
.debounce(for: .milliseconds(250), scheduler: RunLoop.main, options: nil)
.sink(receiveValue: { fragment in
self.status = .isSearching
if !fragment.isEmpty {
self.searchCompleter.queryFragment = fragment
} else {
self.status = .idle
self.searchResults = []
}
})
}
extension LocationService: MKLocalSearchCompleterDelegate {
func completerDidUpdateResults(_ completer: MKLocalSearchCompleter) {
// out a lot of places and only shows cities and countries.
self.searchResults = completer.results.filter({ $0.subtitle == "" })
self.status = completer.results.isEmpty ? .noResults : .result
}
func completer(_ completer: MKLocalSearchCompleter, didFailWithError error: Error) {
self.status = .error(error.localizedDescription)
}
}
答案 0 :(得分:2)
CoreLocation
框架为您提供了 CLGeocoder
,它可以尝试在两个方向的坐标和地名之间进行转换。
你可以在 Playground 中试试这个,看看它是如何工作的:
import Foundation
import CoreLocation
func getCoordinate( addressString : String,
completionHandler: @escaping(CLLocationCoordinate2D, NSError?) -> Void ) {
let geocoder = CLGeocoder()
geocoder.geocodeAddressString(addressString) { (placemarks, error) in
if error == nil {
if let placemark = placemarks?[0] {
let location = placemark.location!
completionHandler(location.coordinate, nil)
return
}
}
completionHandler(kCLLocationCoordinate2DInvalid, error as NSError?)
}
}
let valid = "New Orleans, Louisiana, USA"
let invalid = "The Moon"
getCoordinate(addressString: valid) { location, error in
guard error == nil else {print("Error:"); return}
print(location)
}
getCoordinate(addressString: invalid) { location, error in
guard error == nil else {print("Error:"); return}
print(location)
}
结果是异步返回的,因此您需要提供一个完成处理程序。