JSON 可解码 swift 4
JSON decodable swift 4
我在为以下 JSON 创建 public 结构时遇到了麻烦。我正在尝试提取温度和湿度。我试图提取以下 JSON 但我认为我在识别每个变量的方式上遇到了问题。
这是JSON:
{"coord":{"lon":-82.26,"lat":27.76},"weather":[{"id":804,"main":"Clouds","description":"overcast clouds","icon":"04n"}],"base":"stations","main":{"temp":66.24,"pressure":1021,"humidity":63,"temp_min":62.6,"temp_max":69.8},"visibility":16093,"wind":{"speed":8.05,"deg":80},"clouds":{"all":90},"dt":1523500500,"sys":{"type":1,"id":726,"message":0.0051,"country":"US","sunrise":1523531237,"sunset":1523577156},"id":420006939,"name":"Brandon","cod":200}
这是结构
public struct Page: Decodable {
private enum CodingKeys : String, CodingKey {
case coord = "coord", weather = "weather", mainz = "main", visibility = "visibility", wind = "wind", clouds = "clouds", dt = "dt", sys = "sys", id = "id", name = "name", cod = "cod"}
let coord: String
let weather: [String]
let mainz: String
let visibility: Int
let wind: String
let clouds: String
let dt: Int
let sys: String
let id: Int
let name: String
let cod: Int
public struct Main: Decodable {
private enum CodingKeys : String, CodingKey {
case temp = "temp", pressure = "pressure",humidity = "humidity", temp_min = "temp_min", temp_max = "temp_max"
}
let temp: Int
let pressure: Int
let humidity: Int
let temp_min: Int
let temp_max: Int
}
...以及我正在使用解码的代码...
// Make the POST call and handle it in a completion handler
let task = session.dataTask(with: components.url!, completionHandler: {(data, response, error) in
guard let data = data else { return }
do
{
let result = try JSONDecoder().decode(Page.self, from: data)
for main in result.mainz {
print(main.humidity)
}
}catch
{print("Figure it out")
}
})
task.resume()
创建结构来捕捉你想要的任何东西。例如,如果您对温度和坐标感兴趣,请为它们创建结构:
struct WeatherTemperature: Codable {
let temp: Double
let pressure: Double
let humidity: Double
let tempMin: Double
let tempMax: Double
}
struct WeatherCoordinate: Codable {
let latitude: Double
let longitude: Double
enum CodingKeys: String, CodingKey {
case latitude = "lat"
case longitude = "lon"
}
}
然后为整个响应创建一个结构:
struct ResponseObject: Codable {
let coord: WeatherCoordinate
let main: WeatherTemperature
}
注意,我只为我关心的键创建属性。
然后解码:
let decoder = JSONDecoder()
decoder.keyDecodingStrategy = .convertFromSnakeCase
do {
let responseObject = try decoder.decode(ResponseObject.self, from: data)
print(responseObject.coord)
print(responseObject.main)
} catch {
print(error)
}
结果是:
WeatherCoordinate #1(latitude: 27.760000000000002, longitude: -82.260000000000005)
WeatherTemperature #1(temp: 66.239999999999995, pressure: 1021.0, humidity: 63.0, tempMin: 62.600000000000001, tempMax: 69.799999999999997)
显然,添加您关心的任何其他 structures/properties,但希望这能说明这个想法。
请注意,我不想让 JSON 决定我的 属性 名称,因此,例如,我为我的解码器指定了一个关键解码策略以从 JSON 转换snake_case 到 Swift 驼峰式。
我也喜欢更长的 属性 名字,所以我想要更具表现力的名字(latitude
和 longitude
而不是 lat
和 lon
),我为那些定义了 CodingKeys
。但是在这个分数上做任何你想做的事情。
我在为以下 JSON 创建 public 结构时遇到了麻烦。我正在尝试提取温度和湿度。我试图提取以下 JSON 但我认为我在识别每个变量的方式上遇到了问题。
这是JSON:
{"coord":{"lon":-82.26,"lat":27.76},"weather":[{"id":804,"main":"Clouds","description":"overcast clouds","icon":"04n"}],"base":"stations","main":{"temp":66.24,"pressure":1021,"humidity":63,"temp_min":62.6,"temp_max":69.8},"visibility":16093,"wind":{"speed":8.05,"deg":80},"clouds":{"all":90},"dt":1523500500,"sys":{"type":1,"id":726,"message":0.0051,"country":"US","sunrise":1523531237,"sunset":1523577156},"id":420006939,"name":"Brandon","cod":200}
这是结构
public struct Page: Decodable {
private enum CodingKeys : String, CodingKey {
case coord = "coord", weather = "weather", mainz = "main", visibility = "visibility", wind = "wind", clouds = "clouds", dt = "dt", sys = "sys", id = "id", name = "name", cod = "cod"}
let coord: String
let weather: [String]
let mainz: String
let visibility: Int
let wind: String
let clouds: String
let dt: Int
let sys: String
let id: Int
let name: String
let cod: Int
public struct Main: Decodable {
private enum CodingKeys : String, CodingKey {
case temp = "temp", pressure = "pressure",humidity = "humidity", temp_min = "temp_min", temp_max = "temp_max"
}
let temp: Int
let pressure: Int
let humidity: Int
let temp_min: Int
let temp_max: Int
}
...以及我正在使用解码的代码...
// Make the POST call and handle it in a completion handler
let task = session.dataTask(with: components.url!, completionHandler: {(data, response, error) in
guard let data = data else { return }
do
{
let result = try JSONDecoder().decode(Page.self, from: data)
for main in result.mainz {
print(main.humidity)
}
}catch
{print("Figure it out")
}
})
task.resume()
创建结构来捕捉你想要的任何东西。例如,如果您对温度和坐标感兴趣,请为它们创建结构:
struct WeatherTemperature: Codable {
let temp: Double
let pressure: Double
let humidity: Double
let tempMin: Double
let tempMax: Double
}
struct WeatherCoordinate: Codable {
let latitude: Double
let longitude: Double
enum CodingKeys: String, CodingKey {
case latitude = "lat"
case longitude = "lon"
}
}
然后为整个响应创建一个结构:
struct ResponseObject: Codable {
let coord: WeatherCoordinate
let main: WeatherTemperature
}
注意,我只为我关心的键创建属性。
然后解码:
let decoder = JSONDecoder()
decoder.keyDecodingStrategy = .convertFromSnakeCase
do {
let responseObject = try decoder.decode(ResponseObject.self, from: data)
print(responseObject.coord)
print(responseObject.main)
} catch {
print(error)
}
结果是:
WeatherCoordinate #1(latitude: 27.760000000000002, longitude: -82.260000000000005)
WeatherTemperature #1(temp: 66.239999999999995, pressure: 1021.0, humidity: 63.0, tempMin: 62.600000000000001, tempMax: 69.799999999999997)
显然,添加您关心的任何其他 structures/properties,但希望这能说明这个想法。
请注意,我不想让 JSON 决定我的 属性 名称,因此,例如,我为我的解码器指定了一个关键解码策略以从 JSON 转换snake_case 到 Swift 驼峰式。
我也喜欢更长的 属性 名字,所以我想要更具表现力的名字(latitude
和 longitude
而不是 lat
和 lon
),我为那些定义了 CodingKeys
。但是在这个分数上做任何你想做的事情。