JSON数据 和 模型数据 的转换可以直接使用 Encodable & Decodable 来解决

前提：模型类 必须遵循协议 Codable（包含 Encodable & Decodable）

主要方法：JSONDecoder().decode(<#T##type: Decodable.Protocol##Decodable.Protocol#>, from: <#T##Data#>) 和 JSONEncoder().encode(<#T##value: Encodable##Encodable#>)

代码：

class DataHelper {
class func arrToDict<T: Encodable>(_ arr: [T], _ key: String? = "1") -> [String: Any]? {
    let encode = JSONEncoder()
    encode.outputFormatting = .prettyPrinted
    
    var dict: [String: Any] = [:]
    var arrM: [[String: Any]?] = []
    
    for model in arr {
        autoreleasepool {
            if let data = try? encode.encode(model) {
                if let dic = ((try? JSONSerialization.jsonObject(with: data, options: .mutableLeaves) as? [String: Any]) as [String : Any]??) {
                    arrM.append(dic)
                }
            }
        }
    }
    dict.updateValue(arrM, forKey: key!)
    print("- arrToDict -", dict)
    
    return dict
}

class func modelToDict<T: Encodable>(_ model: T) -> [String: Any]? {
    let encode = JSONEncoder()
    encode.outputFormatting = .prettyPrinted
    guard let data = try? encode.encode(model) else {return nil}
    guard let dic = ((try? JSONSerialization.jsonObject(with: data, options: .mutableLeaves) as? [String: Any]) as [String : Any]??) else {return nil}
    
    return dic
}

class func modelToStr<T: Encodable>(_ model: T) -> String? {
    let encode = JSONEncoder()
    encode.outputFormatting = .prettyPrinted
    guard let data = try? encode.encode(model) else {return nil}
    guard let dic = ((try? JSONSerialization.jsonObject(with: data, options: .mutableLeaves) as? String) as String??) else {return nil}
    
    return dic
}

class func dictToArr<T: Decodable>(_ dic: [String: Any], _ key: String? = "1") -> [T]? {
    guard let arr = dic[key!] as? [Any] else {return nil}
    
    var result: [T] = []
    for dict in arr {
        autoreleasepool {
            if let data = try? JSONSerialization.data(withJSONObject: dict, options: .prettyPrinted) {
                if let value = try? JSONDecoder().decode(T.self, from: data) {
                    result.append(value)
                }
            }
        }
    }
    
    print("- dictToArr -", arr, result)
    
    return result
}

class func dictToModel<T: Decodable>(_ dic: [String: Any]) -> T? {
    guard let data = try? JSONSerialization.data(withJSONObject: dic, options: .prettyPrinted) else {return nil}
    guard let result = try? JSONDecoder().decode(T.self, from: data) else {return nil}
    
    return result
}

class func strToModel<T: Decodable>(_ str: String) -> T? {
    guard let data = try? JSONSerialization.data(withJSONObject: str, options: .prettyPrinted) else {return nil}
    guard let result = try? JSONDecoder().decode(T.self, from: data) else {return nil}
    
    return result
}

class func dataToModel<T: Decodable>(_ data: Data) -> T? {
    guard let result = try? JSONDecoder().decode(T.self, from: data) else {return nil}
    
    return result
}
}