Question

我正在尝试调用一个我从API中提取数据的函数。该函数在var body: some View部分之前创建，并在其中调用。函数本身或其他任何地方都没有编译器错误。在我开始使用SwiftUI之前，我对这种类型的功能没有任何疑问，并且代码几乎完全相同。这是包含JSON数据的Struct函数的代码；

var postDetailsData = postDetails.self
   var commentsArray = comments.self

   struct postDetails: Decodable {
       let count: Int?
       var results: [results]
   }
       struct results: Decodable {
           var id: String
           let author: author?
           let anonym: Bool
           let subscribed: Bool
           let created: String
           let active: Bool
           let text: String
           let image: String?
           let comments: [comments]

       }
           struct author: Decodable {
               let user: Int
               var name: String
               let avatar: String?
               let banned: Bool
           }
           struct comments: Decodable, Identifiable {
               let id: Int
               let text: String
               let author: authorOfComment?
           }
               struct authorOfComment: Decodable {
                   let name: String
                   let avatar: String?
       }

//And now the actual function

  let tokenData = UserDefaults.standard.object(forKey: "savedToken")

   var spread = Bool()
   let request = NSMutableURLRequest(url: NSURL(string: "http://localhost:8000/areas/sample/")! as URL,
                                           cachePolicy: .useProtocolCachePolicy,
                                           timeoutInterval: 10.0)

  func pullData(){
          let headers = [
              "Authorization": "token \(tokenData ?? "nope")",
              "cache-control": "no-cache",
              "Postman-Token": "53853353-f547-410a-b289-e3c4ced8e426"
          ]

          request.httpMethod = "GET"
          request.allHTTPHeaderFields = headers

          let session = URLSession.shared
          let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
              if (error != nil) {
                  print(error)
              }
              guard let data = data else {return}

              do{
                  let JSONFromServer = try JSONSerialization.jsonObject(with: data, options: .allowFragments)
                  print(JSONFromServer)
                  let decoder = JSONDecoder()
                  decoder.keyDecodingStrategy = .convertFromSnakeCase
                  let postDetailsDataArray = try decoder.decode(postDetails.self, from: data)
                  print(postDetailsDataArray.results)
                  for results in postDetailsDataArray.results{
                      DispatchQueue.main.async {
                          //Account Pic Post and Other Stuff In The HStack
                    let accountPicAndStuff =  HStack {


                       Button(action: /*@START_MENU_TOKEN@*/{}/*@END_MENU_TOKEN@*/) {
                               ImageWithActivityIndicator(imageURL: results.author?.avatar ?? "")
                               .frame(width: 30, height: 30)
                               .clipShape(Circle())
                               .offset(x: -75, y: 0)
                           }

                           Text(results.author?.name ?? "Annon")
                               .offset(x: -75)
                           Button(action: /*@START_MENU_TOKEN@*/{}/*@END_MENU_TOKEN@*/) {
                            Image("BookMark").offset(x: 70)
                           }
                           Button(action: /*@START_MENU_TOKEN@*/{}/*@END_MENU_TOKEN@*/) {
                            Image("more-vertical").offset(x: 70)
                           }

                       }.offset(y: 65)

                       //accountPicAndStuff.offset(y: 65)

                          //Description code (pulls data from api)

                          var postTextTest = results.text

                       Text(results.text)
                       //.padding(.bottom, 0)
                       .offset(y: 10)
                       .lineLimit(4)

                       //Image From Post Stuff
                       if results.image == nil{
                           print("no image")
                       }else{
                       ImageWithActivityIndicator(imageURL: results.image ?? "")
                       .offset(y: 50)
                       .scaledToFit()
                       }
                          //Date and time for post
                       Text(results.created)
                           .font(.footnote)
                           .fontWeight(.light)
                           .foregroundColor(Color.gray)
                           .multilineTextAlignment(.leading)
                           .offset(x: -85, y: 50)

                          for comments in results.comments{
                              print(comments)
                                  //Comment View Code using Lists

                           List(results.comments){ comments in
                               HStack{
                                   ImageWithActivityIndicator(imageURL: comments.author?.avatar ?? "")
                                   .frame(width: 100.0, height: 100.0)
                               }
                            }
                          }
                      }
                  }
              }catch{
                  print("Failed to decode:", error)
              }
          })
          dataTask.resume()
      }

这就是我调用函数的方式；

struct FunAreaSmall: View {

//Code from above goes here...

    var body: some View {
        //Smaller UI
                       VStack {
                       pullData()

                           HStack {
                                      Button(action:{}) {
                                       Image("SkipBtn")
                                           .offset(y: 60)
                                           .scaledToFit()
                                      }
                                   Button(action: {}) {
                                       Image("IgniteBtn")
                                           .offset(y: 60)
                                           .scaledToFit()
                               }
                           }
                }
        }

    }

错误本身

'Int'不能转换为'CGFloat'

出现在HStack的第一个按钮上的.offset(y: 60)上，我知道这不是问题，因为当我注释掉对该函数的调用时，错误消失了。我尝试了各种方法来解决此错误，但我得到的只是更多错误。我试图在Google上查找错误，但没有任何帮助。

感谢您的帮助！

Answer 1

您不能仅将函数调用放在ViewBuilder中，因为它不能解析不透明的返回类型。

根据您的需求，有几种可能的解决方案：

1）将pullData的呼叫放在init()中
2）在ViewBuilder中提供明确的回报（全部）
3）调用如下所示的闭包（似乎在该用例中最合适）：</ p>

struct FunAreaSmall: View {

    //Code from above goes here...
    var body: some View {
        //Smaller UI
        VStack {
            HStack {
                Button(action:{}) {
                    Image("SkipBtn")
                        .offset(y: 60)
                        .scaledToFit()
                }
                Button(action: {}) {
                    Image("IgniteBtn")
                        .offset(y: 60)
                        .scaledToFit()
                }
            }
        }
        .onAppear() {
            self.pullData()
        }
    }
}

'Int'无法转换为'CGFloat'SwiftUI误导性错误

1 个答案: