解码失败 json

Question

你好我想检索json数据，json数据是这样的

"items":[  
  {  
     "date_for":"2018-11-11",
     "fajr":"5:28 am",
     "shurooq":"6:37 am",
     "dhuhr":"11:52 am",
     "asr":"2:40 pm",
     "maghrib":"5:06 pm",
     "isha":"6:15 pm"
  }
],

然后我像这样为 JSONDecoder 解码：

struct PrayerModel: Decodable {
var items: [Items]
}

struct Items: Decodable {
var fajr: String
var dhuhr: String
var asr: String
var maghrib: String
var isha: String

init(dictionary: [String: String]) {
    self.fajr = dictionary["fajr"] ?? ""
    self.dhuhr = dictionary["dhuhr"] ?? ""
    self.asr = dictionary["asr"] ?? ""
    self.maghrib = dictionary["maghrib"] ?? ""
    self.isha = dictionary["isha"] ?? ""
  }
}

然后我创建一个对象来存储可解码数据：

struct Prayer {
var prayerName: String
var prayerIcon: UIImage
var prayerTime: String

init(prayerName: String, prayerIcon: UIImage, prayerTime: String) {
    self.prayerName = prayerName
    self.prayerIcon = prayerIcon
    self.prayerTime = prayerTime
 }
}

并使用 URLSession 检索它：

do {
     let prayerData = try JSONDecoder().decode(PrayerModel.self, from: data)

     prayerData.items.forEach({ (item) in
     let isya = Prayer(prayerName: "Isya", prayerIcon: #imageLiteral(resourceName: "Clear"), prayerTime: item.isha)
     self.prayers.append(contentsOf: [shubuh, dzuhur, ashar, maghrib, isya])
      })
        DispatchQueue.main.async {
        self.tableView.reloadData()
       }
            } catch let decodeErr {
                print("Failed to decode:", decodeErr)
            }

我得到了这个错误

Failed to decode: dataCorrupted(Swift.DecodingError.Context(codingPath: [], debugDescription: "The given data was not valid JSON.", underlyingError: Optional(Error Domain=NSCocoaErrorDomain Code=3840 "JSON text did not start with array or object and option to allow fragments not set." UserInfo={NSDebugDescription=JSON text did not start with array or object and option to allow fragments not set.})))

我的代码哪里有问题，有人可以帮忙吗？

Answer 1

如果您想将 Decodable 原型与您的 JSON 一起使用，则变量应具有完全相同的名称并包括具有相同位置的所有项目。

试试这个：

var date_for: String
var fajr: String
var shurooq: String
var dhuhr: String
var asr: String
var maghrib: String
var isha: String

init(dictionary: [String: String]) {
    self.date_for = dictionary["date_for"] ?? ""
    self.fajr = dictionary["fajr"] ?? ""
    self.shurooq = dictionary["shurooq"] ?? ""
    self.dhuhr = dictionary["dhuhr"] ?? ""
    self.asr = dictionary["asr"] ?? ""
    self.maghrib = dictionary["maghrib"] ?? ""
    self.isha = dictionary["isha"] ?? ""
}

Answer 2

正如我在评论中提到的，json 消息不正确，我向其中添加了 {}，它运行良好。

{"items":[{
"date_for":"2018-11-11", "fajr":"5:28 am", "shurooq":"6:37 am", "dhuhr":"11:52 am", "asr":"2:40 pm", "maghrib":"5:06 pm", "isha":"6:15 pm"
}] }

如果您不想使用它们，则不必在 json 消息中包含所有元素，我从 Items 中删除了 init() 方法，因为它不是用过的。

struct Items: Decodable {
  var fajr: String
  var dhuhr: String
  var asr: String
  var maghrib: String
  var isha: String
}

然后它与下面的代码一起工作得很好

let str = "{\"items\":[{\"date_for\":\"2018-11-11\",\"fajr\":\"5:28 am\",\"shurooq\":\"6:37 am\",\"dhuhr\":\"11:52 am\",\"asr\":\"2:40 pm\",\"maghrib\":\"5:06 pm\",\"isha\":\"6:15 pm\"}]}"

do {
  if let data = str.data(using: .utf8) {
    let prayerData = try JSONDecoder().decode(PrayerModel.self, from: data)
    for item in prayerData.items {
      print(item)
    }
  }
} catch let decodeErr {
  print("Failed to decode:", decodeErr)
}

解码失败 json

Failed to decode json

json

ios

swift

decodable