如何使用 SwiftUI 显示解析的数据? [英] How to show parsed data with SwiftUI?

问题描述

我正在尝试使用 SwiftUI 在视图中显示从 API 解析的数据.

I'm trying to show in a view parsed data from an API using SwiftUI.

我正在使用此代码正确获取数据:

I'm fetching correctly the data using this code:

import UIKit

class APIController: ObservableObject {
    
    func apiCall() {
        
        // URL
        let url = URL(string: "https://geek-jokes.p.rapidapi.com/api?format=json")
        
        guard url != nil else {
            print("Error creating url object")
            return
        }
        
        // URL Rquest
        var request = URLRequest(url: url!, cachePolicy: .useProtocolCachePolicy, timeoutInterval: 10)
        
        // Specify the header
        let headers = [
            "x-rapidapi-key": "d1363cbe66msh266920b6366eaacp1f87dfjsn050e3f8e58e2",
            "x-rapidapi-host": "geek-jokes.p.rapidapi.com"
        ]
        
        request.allHTTPHeaderFields = headers
        
        //     Specify the body
        //        let jsonObject = [
        //            "sign": "Aries"
        //        ] as [String:Any]
        //
        //        do {
        //        let requestBody = try JSONSerialization.data(withJSONObject: jsonObject, options: .fragmentsAllowed)
        //
        //            request.httpBody = requestBody
        //        }
        //        catch {
        //            print("Error creating the data object from json")
        //        }
        
        // Set the request type
        request.httpMethod = "GET"
        
        // Get the URLSession
        let session = URLSession.shared
        
        // Create the data task
        let dataTask = session.dataTask(with: request) { data, response, error in
            
            // Check for errors
            if error == nil && data != nil {
                
                //          Try to parse out the JSON data
                let decoder = JSONDecoder()
                
                do {
                    let jokesData = try decoder.decode(JokesData.self, from: data!)
                    
                    print(jokesData)
                }
                catch {
                    print("Error in JSON parsing")
                }
                
                //             Try to print out the JSON data
                //                do {
                //                    let dictionary = try JSONSerialization.jsonObject(with: data!, options: .mutableContainers) as? [String:Any]
                //                    print(dictionary)
                //
                //                }
                //                catch {
                //                    print("Error parsing response data")
                //                }
                
            }
        }
        
        // Fire off the data task
        dataTask.resume()
        
    }
    
}

然后我不确定是否在 JokesData.swift 中正确导入了数据

Then I'm not sure if the data is correctly imported in JokesData.swift

import foundation

struct JokesData: Codable {

    var joke:String = ""

}

当我尝试在 JokesView.swift 中加载数据时，什么也没有出现:(

And when I try to load the data in JokesView.swift, nothing appear :(

import SwiftUI

struct JokesView: View {

    var jokesData: JokesData

    @StateObject var viewRouter: ViewRouter

    var body: some View {
        Text(jokesData.joke)
            .foregroundColor(.black)
    }
}

如果有人知道我做错了什么，那将非常有帮助.

If someone has an idea of what I did wrong, it would be very helpful.

推荐答案

• 在APIController中添加一个属性

  @Published var jokesData = JokesData() 
  

• 用

• Replace the do - catch block in the completion handler with

    do {
        let jokesData = try decoder.decode(JokesData.self, from: data!)
  
        print(jokesData)
        DispatchQueue.main.async {
            self.jokesData = jokesData
        }
  
    }
    catch {
        print(error)
    }
  

  它将接收到的数据分配给发布的 jokesData 属性.

  it assigns the received data to the publishing jokesData property.

  在视图中创建控制器的@StateObject，在onAppear修饰符中加载数据，视图会自动更新.

  In the view create a @StateObject of the controller, in the onAppear modifier load the data, the view will be updated automatically.

  import SwiftUI
  
  struct JokesView: View {
  
      @StateObject var apiController = APIController()
  
      var body: some View {
          Text(apiController.jokesData.joke)
              .foregroundColor(.black)
              .onAppear() {
                  apiController.apiCall()
              }
      }
  }
  

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