Swiftui 无法读取数据，因为它的格式不正确

Question

当我使用 api 运行代码时出现上述错误。我仔细检查了复制 json 文件并在本地运行它正常工作，我似乎无法得到错误来自哪里，

Countries.swift

struct APIResult: Codable {
    var data: APICountryData
}

struct APICountryData: Codable {
    var count: Int
    var results: [Countries]
}

struct Countries: Identifiable, Codable {
    var id: String
    var name: String
    var abrname: String
    var flag_url: URL
    var info: String
}

CountriesViewModel.swift

class CountriesViewModel: ObservableObject {
    
    @Published var searchQuery = ""
    
    var searchCancellable: AnyCancellable? = nil
    
    //Fetched Data....
    @Published var fetchCountries: [Countries]? = nil
        
    @Published var offset: Int = 0
    
    init() {
        
        searchCancellable = $searchQuery
            .removeDuplicates()
            .debounce(for: 0.6, scheduler: RunLoop.main)
            .sink(receiveValue: { str in
                if str == ""{
                    // reset Data...
                    self.fetchCountries = nil
                } else {
                    //search Data...
                    self.searchCountry()
                }
            })
    }
    
    
    
    func searchCountry() {
        
        let url = "my api url"
        
        let session = URLSession(configuration: .default)
        
        session.dataTask(with: URL(string: url)!) { (data, _, err) in
            
            if let error = err{
                print(error.localizedDescription)
                return
            }
            
            guard let APIData = data else {
                print("No Data found")
                return
            }
            
            do {
                
                // Decoding API Data....
                let countrys = try JSONDecoder().decode(APIResult.self, from: APIData)
                
                DispatchQueue.main.async {
                    
                    if self.fetchCountries == nil {
                        self.fetchCountries = countrys.data.results
                    }
                }
            }
            catch{
                print(error.localizedDescription)
            }
            
        }
        .resume()
    }
    
}

当我在模拟器上测试它运行时，但是当我搜索它时出现这个错误“无法读取数据，因为它的格式不正确。”

我的 json 数据示例

[
    {
        "id" : "0",
        "name" : "Afghanistan",
        "abrname" : "AFG",
        "flag_url" : "Image URL",
        "info" : "Afghanistan (/æfˈɡænɪstæn, æfˈɡɑËnɪstÉ‘Ën/ (About this soundlisten);[23] Pashto/Dari: اÙغانستان AfÄ¡ÄnestÄn, Pashto pronunciation: [afɣɑnɪstÉ‘n], Dari pronunciation: [afɣɒËnɪstÉ’Ën]), officially the Islamic Emirate of Afghanistan, is a landlocked country at the crossroads of Central and South Asia. It is bordered by Pakistan to the east and south, Iran to the west, Turkmenistan and Uzbekistan to the north, and Tajikistan and China to the northeast. Occupying 652,864 square kilometres (252,072 sq mi), the country is predominately mountainous with plains in the north and the southwest that are separated by the Hindu Kush mountains. Its population as of 2020 is 31.4 million, composed mostly of ethnic Pashtuns, Tajiks, Hazaras, and Uzbeks. Kabul serves as its capital and largest city."
    },
    {
        "id" : "1",
        "name" : "Andorra",
        "abrname" : "AND",
        "flag_url" : "Image URL",
        "info" : "Andorra[g], officially the Principality of Andorra,[1][h] is a sovereign landlocked microstate on the Iberian Peninsula, in the eastern Pyrenees, bordered by France to the north and Spain to the south. Believed to have been created by Charlemagne, Andorra was ruled by the count of Urgell until 988, when it was transferred to the Roman Catholic Diocese of Urgell. The present principality was formed by a charter in 1278. It is headed by two co-princes: the Bishop of Urgell in Catalonia, Spain and the President of France. Its capital and also its largest city is Andorra la Vella. "
    }
]

Answer 1

你的设计错了。

替换

let countrys = try JSONDecoder().decode(APIResult.self, from: APIData)
            
DispatchQueue.main.async {
                
    if self.fetchCountries == nil {
        self.fetchCountries = countrys.data.results
    }
}

有

let countries = try JSONDecoder().decode([Countries].self, from: APIData)
            
DispatchQueue.main.async {
    self.fetchCountries = countries
}

其他两个结构没有意义。

并将fetchCountries 声明为非可选的空数组，并将结构命名为单数形式Country。