在 Swift 5/Swiftui 中重构 MapView（没有 Coordinators / UIViewRepresentables）
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【中文标题】在 Swift 5/Swiftui 中重构 MapView（没有 Coordinators / UIViewRepresentables）【英文标题】：Refactor a MapView in Swift 5/Swiftui (Without Coordinators / UIViewRepresentables) 【发布时间】：2021-07-03 17:47:54 【问题描述】：我现在有我想要的行为，但我想重构这段代码。我想把所有的地图逻辑从我的视野中移开。
在持有这张地图的视图中，我有以下内容：
import SwiftUI
import MapKit
struct PostActivityView: View
@EnvironmentObject var viewModel: ActivitiesViewModel
@EnvironmentObject var user: UserViewModel
@State var region: MKCoordinateRegion
@Binding var parentsTab: Tab
@State private var locations = [MKPointAnnotation]()
@State private var userTracking = MapUserTrackingMode.follow
.
.
.
ZStack
Map(coordinateRegion: $region, interactionModes: [MapInteractionModes.all], showsUserLocation: true, userTrackingMode: $userTracking)
.frame( height: 386)
.frame(height: 256)
.cornerRadius(25.0)
.shadow(radius: 10.0, x: 20, y: 10)
Circle()
.fill(Color.blue)
.opacity(0.3)
.frame(width: 16, height: 16)
Circle()
.fill(Color.black)
.opacity(0.3)
.frame(width: 1, height: 1)
HStack
Spacer()
VStack
Spacer()
HStack()
VStack()
Button(action: zoom()) Image(systemName: "location.circle.fill")
.background(Color.blue.opacity(0.75))
.foregroundColor(.white)
.font(.title)
.clipShape(Circle())
.rotationEffect(.degrees(30))
VStack()
Button(action: saveCrosshairLocation())
Image(systemName: "checkmark.circle.fill")
.background(Color.blue.opacity(0.75))
.foregroundColor(.white)
.font(.title)
.clipShape(Circle())
还有这两个功能：
func saveCrosshairLocation()
let newLocation = MKPointAnnotation()
newLocation.coordinate = self.region.center
self.locations.append(newLocation)
let local: CLLocation = CLLocation(latitude: self.region.center.latitude , longitude: self.region.center.longitude)
CLGeocoder().reverseGeocodeLocation(local) (placemarks, error) in
guard error == nil else
print("ReverseGeocode Error: \(String(describing: error))")
return
if let firstPlacemark = placemarks?.first
print(firstPlacemark)
var addressString : String = ""
if firstPlacemark.name != nil
addressString = addressString + firstPlacemark.name! + ", "
else
if firstPlacemark.subThoroughfare != nil
addressString = addressString + firstPlacemark.subThoroughfare! + ", "
if firstPlacemark.thoroughfare != nil
addressString = addressString + firstPlacemark.thoroughfare! + ", "
if firstPlacemark.subLocality != nil
addressString = addressString + firstPlacemark.subLocality! + ", "
if firstPlacemark.locality != nil
addressString = addressString + firstPlacemark.locality! + ", "
if firstPlacemark.country != nil
addressString = addressString + firstPlacemark.country! + ", "
if firstPlacemark.postalCode != nil
addressString = addressString + firstPlacemark.postalCode! + ", "
if firstPlacemark.region != nil
addressString = addressString + "<\(local.coordinate.latitude),\(local.coordinate.longitude)>"
self.eventLocation = addressString
func zoom()
let newZoom = 0.08
self.region = MKCoordinateRegion(center: user.getLocation(), span: MKCoordinateSpan(latitudeDelta: newZoom, longitudeDelta: newZoom))
我想将它重构为它自己的 CustomMapView.swift 。我不确定 Map 是否与当前版本的 Swift 中的 MKMapView 相同。我不确定如何将这一切绑定在一起。对于 customMapView，我希望有几个具有 @Binding 语法的变量，但我在重构时遇到了麻烦。
目标是让我成为更好的程序员，感谢您的帮助。
【问题讨论】：
所以，我有这个 ZStack，它以我喜欢的方式显示地图，以及随之而来的两个功能。这些都在“PostView.Swift”中。我想把它拿出来，并用 CustomMapView($var1, $var2, $var3) 之类的东西替换它。用这种新的 swift 编写方式进行重构仍然有点超出我的技能水平。我希望有人向我展示重构它的正确方法。再说一次，基本上，我希望这张地图是一个组件，我可以只用一行插入。 此代码可能会有所帮助***.com/a/60460829/3891850 【参考方案1】：我的主视图中的代码现在是：
标题：
struct PostActivityView: View
@EnvironmentObject var viewModel: ActivitiesViewModel
@EnvironmentObject var user: UserViewModel
@State var region: MKCoordinateRegion
@Binding var parentsTab: Tab
@State private var locations = [MKPointAnnotation]()
@State private var userTracking = MapUserTrackingMode.follow
.
.
.
主体：
.
.
.
ForPlay_MapView(region: $region, userTracking: $userTracking, locations: $locations, eventLocation: $eventLocation)
.
.
.
地图视图现在是：
import SwiftUI
import MapKit
struct ForPlay_MapView : View
@EnvironmentObject var user: UserViewModel
@Binding var region: MKCoordinateRegion
@Binding var userTracking: MapUserTrackingMode
@Binding var locations: [MKPointAnnotation]
@Binding var eventLocation: String
var body: some View
ZStack
Map(coordinateRegion: $region, interactionModes: [MapInteractionModes.all], showsUserLocation: true, userTrackingMode: $userTracking)
.frame( height: 386)
.frame(height: 256)
.cornerRadius(25.0)
.shadow(radius: 10.0, x: 20, y: 10)
Circle()
.fill(Color.blue)
.opacity(0.3)
.frame(width: 16, height: 16)
Circle()
.fill(Color.black)
.opacity(0.3)
.frame(width: 1, height: 1)
HStack
Spacer()
VStack
Spacer()
HStack()
VStack()
Button(action: zoom()) Image(systemName: "location.circle.fill")
.background(Color.blue.opacity(0.75))
.foregroundColor(.white)
.font(.title)
.clipShape(Circle())
.rotationEffect(.degrees(30))
VStack()
Button(action: saveCrosshairLocation())
Image(systemName: "checkmark.circle.fill")
.background(Color.blue.opacity(0.75))
.foregroundColor(.white)
.font(.title)
.clipShape(Circle())
func saveCrosshairLocation()
let newLocation = MKPointAnnotation()
newLocation.coordinate = self.region.center
self.locations.append(newLocation)
let local: CLLocation = CLLocation(latitude: self.region.center.latitude , longitude: self.region.center.longitude)
CLGeocoder().reverseGeocodeLocation(local) (placemarks, error) in
guard error == nil else
print("ReverseGeocode Error: \(String(describing: error))")
return
if let firstPlacemark = placemarks?.first
print(firstPlacemark)
var addressString : String = ""
if firstPlacemark.name != nil
addressString = addressString + firstPlacemark.name! + ", "
else
if firstPlacemark.subThoroughfare != nil
addressString = addressString + firstPlacemark.subThoroughfare! + ", "
if firstPlacemark.thoroughfare != nil
addressString = addressString + firstPlacemark.thoroughfare! + ", "
if firstPlacemark.subLocality != nil
addressString = addressString + firstPlacemark.subLocality! + ", "
if firstPlacemark.locality != nil
addressString = addressString + firstPlacemark.locality! + ", "
if firstPlacemark.country != nil
addressString = addressString + firstPlacemark.country! + ", "
if firstPlacemark.postalCode != nil
addressString = addressString + firstPlacemark.postalCode! + ", "
if firstPlacemark.region != nil
addressString = addressString + "<\(local.coordinate.latitude),\(local.coordinate.longitude)>"
self.eventLocation = addressString
func zoom()
let newZoom = 0.08
self.region = MKCoordinateRegion(center: user.getLocation(), span: MKCoordinateSpan(latitudeDelta: newZoom, longitudeDelta: newZoom))
【讨论】：
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