SwiftUI:如何从Cloud Firestore获取GeoPoint并显示它? [英] SwiftUI: How to fetch GeoPoint from Cloud Firestore and display it?

问题描述

所以我有这个Cloud Firestore设置，其中每个图像文档都有相同的4个字段，但是具有不同的值.

So I have this Cloud Firestore Setup, where each of the Image Documents have the same 4 fields, but with different values.

然后如何遍历所有图像文档并获得GeoPint?这样我以后可以显示纬度和经度吗?

How can I then iterate over all of the Image Docs and get the GeoPint? So I later can display the Latitude and Longitude?

我猜迭代部分并不重要，所以另一种询问方式是，如何获取Geopoint，然后将其显示在我的项目中?

I Guess the iteration part isn’t THAT important, so antoher way of asking is, how can I get the Geopoint and then display it in my project?

推荐答案

以我的最后一个答案为基础( https://stackoverflow.com/a/66377922/560942 ):

Building on my last answer (https://stackoverflow.com/a/66377922/560942):

struct ImageModel {
  var id = UUID()
  var quote : String
  var url: String
  var position: GeoPoint
} 

images = snapshot.documents.compactMap { documentSnapshot -> ImageModel? in
  let documentData = documentSnapshot.data()
  if let quote = documentData["Quote"] as? String,
    let url = documentData["Url"] as? String,
    let position = documentData["Position"] as? GeoPoint
      {
        return ImageModel(quote: quote, url: url, position: position)
      } else {
        return nil
      }
    }

然后，稍后显示文本坐标:

Then, to display the text coordinates later on:

ForEach(images, id: \.id) { image in 
  Text("Location: \(image.position.latitude), \(image.position.longitude)")
}

更新以显示GeoPoint :

struct GeoPointView : View {
    var position : GeoPoint

    struct IdentifiablePoint: Identifiable {
        var id = UUID()
        var position : GeoPoint
    }
    
    var body: some View {
        Map(coordinateRegion: .constant(
                MKCoordinateRegion(center: CLLocationCoordinate2D(latitude: position.latitude, longitude: position.longitude), span: MKCoordinateSpan(latitudeDelta: 0.005, longitudeDelta: 0.005))), annotationItems: [position].map { IdentifiablePoint(position: $0)}) { point in
            MapPin(coordinate: CLLocationCoordinate2D(latitude: point.position.latitude, longitude: point.position.longitude))
        }
            .frame(width: 200, height: 200)
    }
}

用法:

ForEach(images, id: \.id) { image in 
  Text("Location: \(image.position.latitude), \(image.position.longitude)")
  GeoPointView(position: image.position)
}

如果您要在地图上指的是我，可以根据需要更新此答案，也可以参考Apple开发者论坛上的以下帖子:

In the event you mean on a map, I can update this answer if needed, or you can refer to the following post on the Apple Developer Forums: https://developer.apple.com/forums/thread/651668

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