一、字典轉(zhuǎn)模型
- 現(xiàn)有如下JSON數(shù)據(jù)
let dict: [String : Any] = [
"name" : "zhangsan",
"height" : 1.88,
"pet" : [
"name" : "xiaohei",
"age" : 3
],
"picture": [
[
"url": "這里是url",
"name": "一張圖片"
],
[
"url": "這里是url",
"name": "一張圖片"
]
]
]
- 根據(jù)數(shù)據(jù), 定義三個類:
Person,Pet,Picture, 每個類都遵守Codable協(xié)議
class Person: Codable {
var name: String?
var age: Int?
var h: Double?
var pet: Pet?
var picture: [Picture]?
private enum CodingKeys: String, CodingKey {
case h = "height"
case name
case age
case pet
case picture
}
}
class Pet: Codable {
var name: String?
var age: Int?
}
class Picture: Codable {
var url: String?
var name: String?
}
-
Person類中有如下代碼, 表示屬性h接收J(rèn)SON數(shù)據(jù)中的height字段對應(yīng)的值
private enum CodingKeys: String, CodingKey {
case h = "height"
case name
case age
case pet
case picture
}
- 定義字典轉(zhuǎn)模型方法, 這里使用了泛型
func JSONModel<T>(_ type: T.Type, withKeyValues data:[String:Any]) throws -> T where T: Decodable {
let jsonData = try JSONSerialization.data(withJSONObject: data, options: [])
let model = try JSONDecoder().decode(type, from: jsonData)
return model
}
- 調(diào)用字典轉(zhuǎn)模型方法
if let p = try? JSONModel(Person.self, withKeyValues: dict) {
print(p.name, p.h, p.age)
print(p.pet?.name, p.pet?.age)
print(p.picture?.first?.url, p.picture?.first?.name)
}
// 控制臺打印:
Optional("zhangsan") Optional(1.8799999999999999) nil
Optional("xiaohei") Optional(3)
Optional("這里是url") Optional("一張圖片")
這里類的所有屬性都是可選類型, 這是因為當(dāng)類中的屬性, 在JSON數(shù)據(jù)中沒有對應(yīng)
key時,
1浑测、如果屬性非可選, 就會轉(zhuǎn)模型失敗
2嗤无、如果屬性可選, 這個屬性就不會被賦值, 并且模型轉(zhuǎn)換成功
二秤涩、數(shù)組轉(zhuǎn)模型數(shù)組
- 現(xiàn)有如下JSON數(shù)組
let list: [[String:Any]] = [
[
"name" : "zhangsan",
"age" : 20
],
[
"name" : "lisi",
"age" : 18
],
[
"name" : "wangwu",
"age" : 25
]
]
- 定義數(shù)組轉(zhuǎn)模型數(shù)組方法
func JSONModels<T>(_ type: T.Type, withKeyValuesArray datas: [[String:Any]]) throws -> [T] where T: Decodable {
var temp: [T] = []
for data in datas {
let model = try JSONModel(type, withKeyValues: data)
temp.append(model)
}
return temp
}
- 調(diào)用數(shù)組轉(zhuǎn)模型數(shù)組方法
if let ps = try? JSONModels(Person.self, withKeyValuesArray: list) {
for p in ps {
print(p.name, p.age)
}
}
// 控制臺打印:
Optional("zhangsan") Optional(20)
Optional("lisi") Optional(18)
Optional("wangwu") Optional(25)
三傀履、上面用到的兩個方法
/// 字典 -> 模型
///
/// - Parameters:
/// - type: 類型
/// - data: 字典數(shù)據(jù)
/// - Returns: 模型結(jié)果
/// - Throws: 錯誤處理
func JSONModel<T>(_ type: T.Type, withKeyValues data:[String:Any]) throws -> T where T: Decodable {
let jsonData = try JSONSerialization.data(withJSONObject: data, options: [])
let model = try JSONDecoder().decode(type, from: jsonData)
return model
}
/// 字典數(shù)組 -> 模型數(shù)組
///
/// - Parameters:
/// - type: 類型
/// - datas: 字典組數(shù)
/// - Returns: 模型數(shù)組結(jié)果
/// - Throws: 錯誤處理
func JSONModels<T>(_ type: T.Type, withKeyValuesArray datas: [[String:Any]]) throws -> [T] where T: Decodable {
var temp: [T] = []
for data in datas {
let model = try JSONModel(type, withKeyValues: data)
temp.append(model)
}
return temp
}
