尝试从函数中 access/modify SwiftUI 变量

Question

我正在尝试从 JSON 获取数据。到目前为止，我可以提取它并打印它。

我现在的目标是能够在我的 ContentView 中使用它，以便它可以在文本视图或类似的东西中使用。我试过创建 @State 变量，将其作为参数传递等等，但似乎没有任何效果。

我是 SwiftUI 的新手，非常感谢您的帮助！

struct GeoService: Codable {
    var status: String
    var results: [GeoResult]
}

struct GeoResult: Codable {
    
    struct Geometry: Codable {
        
        struct Location: Codable {
            
            let lat: Float
            let lng: Float
            
            init() {
                lat = 32
                lng = 30
            }
        }
        let location: Location
    }
    let formatted_address: String
    let geometry: Geometry
}



struct ContentView: View {

//    @State private var results: Any ?????????
    
    var body: some View {
        NavigationView {
            Text("Test")
                .navigationTitle("Quotes")
                .task {
                    await handleData()
                }
        }
        
    }
    
    func handleData() async {
        let geoResult="""
        {
          "results": [
            {
              "formatted_address": "1600 Amphitheatre Parkway, Mountain View, CA 94043, USA",
              "geometry": {
                "location": {
                  "lat": 37.4224764,
                  "lng": -122.0842499
                }
              }
            },
            {
              "formatted_address": "Test addresss",
              "geometry": {
                "location": {
                  "lat": 120.32132145,
                  "lng": -43.90235469
                }
              }
            }
          ],
          "status": "OK"
        }
        """.data(using: .utf8)!
        
        let decoder = JSONDecoder()
        print("executing handleData()")
        do {
            let obj = try decoder.decode(GeoService.self, from: geoResult)
            for result in obj.results {
                print("Address: \(result.formatted_address)")
                print("Lat/long: (\(result.geometry.location.lat), \(result.geometry.location.lng))")
            }
        } catch {
            print("Did not work :(")
        }
    }
}

Answer 1

我将 get 请求移到了它自己的 class，这样我们就可以利用 ObservableObject 和 Publish 数据。发布数据允许订阅视图在发布的数据发生变化时更新数据。在这种情况下，您的 ContentView 通过 @ObservedObject var geoData: ResponseData 代码行订阅数据。

另外，我在您的视图中添加了如何访问两条相关数据，并以列表形式显示，以便于阅读。这应该让您了解如何 access/display 数据。

希望这能为您提供足够的信息来调整答案，使其按照您想要的方式工作。

import SwiftUI

struct GeoService: Codable {
    var status: String?
    var results: [GeoResult]?
}

struct GeoResult: Codable {

 struct Geometry: Codable {
    
    struct Location: Codable {
        
        let lat: Float
        let lng: Float
        
        init() {
            lat = 32
            lng = 30
        }
    }
    let location: Location
}

let formatted_address: String
    let geometry: Geometry
}

struct ContentView: View {
 @ObservedObject var geoData: ResponseData

 var body: some View {
    NavigationView {
        if #available(iOS 15.0, *) {
            List {
                Text(geoData.geoResultsData?.results?[0].formatted_address ?? "Loading")
                Text(String(geoData.geoResultsData?.results?[0].geometry.location.lat ?? 0))
            }
            .navigationTitle("Quotes")
            .task {
                await geoData.handleData()
                print(geoData.geoResultsData, "yessssss")
            }
        } else {
            Text("failure")
        }
    }
  }
}

class ResponseData: ObservableObject {

@Published var geoResultsData: GeoService?

func handleData() async {
    let geoResult="""
    {
      "results": [
        {
          "formatted_address": "1600 Amphitheatre Parkway, Mountain View, CA 94043, USA",
          "geometry": {
            "location": {
              "lat": 37.4224764,
              "lng": -122.0842499
            }
          }
        },
        {
          "formatted_address": "Test addresss",
          "geometry": {
            "location": {
              "lat": 120.32132145,
              "lng": -43.90235469
            }
          }
        }
      ],
      "status": "OK"
    }
    """.data(using: .utf8)!
    
    let decoder = JSONDecoder()
    print("executing handleData()")
    do {
        let obj = try decoder.decode(GeoService.self, from: geoResult)
        geoResultsData = obj
    } catch {
        print("Did not work :(")
    }
  }
}

编辑：

您需要在您的应用中初始化一些数据。如果需要，您可以暂时将其初始化为空。这可以通过执行以下操作来完成：ContentView(geoData: ResponseData.init())

尝试从函数中 access/modify SwiftUI 变量

Trying to access/modify SwiftUI variable from within a function

iphone

xcode

ios

swift

swiftui