Json 将多个值反序列化为单个属性
我有一个JSON响应,其中包括几个标志:Json 将多个值反序列化为单个属性,json,json.net,Json,Json.net,我有一个JSON响应,其中包括几个标志: {"df":1,"dr":0,"pf":0,"pr":0,"ft":0,"rt":1} 我想将其反序列化为标志枚举: public class Foo { public Doors Doors { get; set; } public Trunk Trunks { get; set; } } df、dr、pf、pr应反序列化为Doors标志枚举,而ft、rt应反序列化为中继。我希望这是定制代码来做出决定。我要找的是能让我说: [Jso
{"df":1,"dr":0,"pf":0,"pr":0,"ft":0,"rt":1}
我想将其反序列化为标志枚举:
public class Foo {
public Doors Doors { get; set; }
public Trunk Trunks { get; set; }
}
df、dr、pf、pr应反序列化为Doors标志枚举,而ft、rt应反序列化为中继。我希望这是定制代码来做出决定。我要找的是能让我说:
[JsonProperty("df,dr,pf,pr"), JsonConverter(typeof(DoorsConverter))]
public Doors Door { get; set; }
这将使我能够根据这些价值来处理房地产的建设。这类事情是否存在,还是我一直在将单个属性推送到非公共字段并在事后构建属性?最近添加到JSON.NET的内容与我们在WCF数据契约中得到的内容类似。有了它,我可以添加一个额外的属性和方法来处理它:
[JsonExtensionData]
public IDictionary<string, JToken> ExtensionData;
[OnDeserialized]
private void OnDeserialized(StreamingContext context)
{
Doors = ExtensionData.ContainsKey("df") && Convert.ToBoolean(Convert.ToInt16(ExtensionData["df"]))
? Doors | Door.DriverSideFront
: Doors & ~Door.DriverSideFront;
Doors = ExtensionData.ContainsKey("dr") && Convert.ToBoolean(Convert.ToInt16(ExtensionData["dr"]))
? Doors | Door.DriverSideRear
: Doors & ~Door.DriverSideRear;
Doors = ExtensionData.ContainsKey("pf") && Convert.ToBoolean(Convert.ToInt16(ExtensionData["pf"]))
? Doors | Door.PassengerSideFront
: Doors & ~Door.PassengerSideFront;
Doors = ExtensionData.ContainsKey("pr") && Convert.ToBoolean(Convert.ToInt16(ExtensionData["pr"]))
? Doors | Door.PassengerSideRear
: Doors & ~Door.PassengerSideRear;
Trunks = ExtensionData.ContainsKey("ft") && Convert.ToBoolean(Convert.ToInt16(ExtensionData["ft"]))
? Trunks | Trunk.Front
: Trunks & ~Trunk.Front;
Trunks = ExtensionData.ContainsKey("rt") && Convert.ToBoolean(Convert.ToInt16(ExtensionData["rt"]))
? Trunks | Trunk.Rear
: Trunks & ~Trunk.Rear;
ExtensionData.Remove("dt");
ExtensionData.Remove("dr");
ExtensionData.Remove("pf");
ExtensionData.Remove("pr");
ExtensionData.Remove("ft");
ExtensionData.Remove("rt");
}
[JsonExtensionData]
公共词典扩展数据;
[已序列化]
私有void已序列化(StreamingContext上下文)
{
Doors=ExtensionData.ContainsKey(“df”)和&Convert.ToBoolean(Convert.ToInt16(ExtensionData[“df”]))
?门|门驱动装置前
:Doors&~Door.DriverSideFront;
Doors=ExtensionData.ContainsKey(“dr”)和&Convert.ToBoolean(Convert.ToInt16(ExtensionData[“dr”]))
?门|门驱动装置
:Doors&~Door.DriverSideRear;
Doors=ExtensionData.ContainsKey(“pf”)和&Convert.ToBoolean(Convert.ToInt16(ExtensionData[“pf”]))
?门|门。乘客前方
:Doors&~Door.PassengerSideFront;
Doors=ExtensionData.ContainsKey(“pr”)和&Convert.ToBoolean(Convert.ToInt16(ExtensionData[“pr”]))
?车门|车门。乘客车门
:Doors&~Door.passengersideriar;
Trunks=ExtensionData.ContainsKey(“ft”)和&Convert.ToBoolean(Convert.ToInt16(ExtensionData[“ft”]))
?行李箱|行李箱。前部
:Trunks和~Trunk.Front;
Trunks=ExtensionData.ContainsKey(“rt”)和&Convert.ToBoolean(Convert.ToInt16(ExtensionData[“rt”]))
?后备箱|后备箱
:后备箱和后备箱;
扩展数据删除(“dt”);
扩展数据删除(“dr”);
ExtensionData.Remove(“pf”);
ExtensionData.Remove(“pr”);
扩展数据删除(“ft”);
ExtensionData.Remove(“rt”);
}
这适用于读取场景。还没有研究过写场景以及它将如何改变情况。我同意@JeffMercado的观点,处理这个问题的最佳方法是创建一个处理整个类的自定义转换器。您在评论中说,创建这样一个转换器是因为您不想编写代码来处理所有其他类属性(问题中未显示),因为它们不需要任何特殊处理。为此,我提出了一个转换器的想法,它将使用JSON.Net的常用机制对所有标准属性进行序列化/反序列化,然后专门处理
Doors
和Trunks
enum字段。因为我不知道你们的其他财产叫什么,所以我只是编了一些与汽车有关的财产。我还将你的Foo
类重命名为Car
,以符合该主题
以下是此示例的类和枚举定义:
public class Car
{
[JsonIgnore]
public Door Doors { get; set; }
[JsonIgnore]
public Trunk Trunks { get; set; }
[JsonProperty("make")]
public string Make { get; set; }
[JsonProperty("model")]
public string Model { get; set; }
[JsonProperty("year")]
public int Year { get; set; }
[JsonProperty("MSRP")]
public decimal MSRP { get; set; }
}
[Flags]
public enum Door
{
None = 0,
DriverSideFront = 1,
DriverSideRear = 2,
PassengerSideFront = 4,
PassengerSideRear = 8
}
[Flags]
public enum Trunk
{
None = 0,
Front = 1,
Rear = 2
}
以下是自定义转换器的代码:
public class CarConverter : JsonConverter
{
private static Dictionary<string, Door> doorMap;
private static Dictionary<string, Trunk> trunkMap;
static CarConverter()
{
doorMap = new Dictionary<string, Door>();
doorMap.Add("df", Door.DriverSideFront);
doorMap.Add("dr", Door.DriverSideRear);
doorMap.Add("pf", Door.PassengerSideFront);
doorMap.Add("pr", Door.PassengerSideRear);
trunkMap = new Dictionary<string, Trunk>();
trunkMap.Add("ft", Trunk.Front);
trunkMap.Add("rt", Trunk.Rear);
}
public override bool CanConvert(Type objectType)
{
return (objectType == typeof(Car));
}
public override object ReadJson(JsonReader reader, Type objectType,
object existingValue, JsonSerializer serializer)
{
JObject jo = JObject.Load(reader);
Car car = jo.ToObject<Car>();
car.Doors = GetDoors(jo);
car.Trunks = GetTrunks(jo);
return car;
}
private Door GetDoors(JObject obj)
{
Door doors = Door.None;
foreach (KeyValuePair<string, Door> kvp in doorMap)
{
if (obj[kvp.Key].Value<int>() == 1)
{
doors |= kvp.Value;
}
}
return doors;
}
private Trunk GetTrunks(JObject obj)
{
Trunk trunks = Trunk.None;
foreach (KeyValuePair<string, Trunk> kvp in trunkMap)
{
if (obj[kvp.Key].Value<int>() == 1)
{
trunks |= kvp.Value;
}
}
return trunks;
}
public override void WriteJson(JsonWriter writer, object value,
JsonSerializer serializer)
{
Car car = (Car)value;
JObject obj = JObject.FromObject(value);
AddDoors(obj, car.Doors);
AddTrunks(obj, car.Trunks);
obj.WriteTo(writer);
}
private void AddDoors(JObject obj, Door doors)
{
foreach (KeyValuePair<string, Door> kvp in doorMap)
{
obj.Add(kvp.Key, ((doors & kvp.Value) != Door.None) ? 1 : 0);
}
}
private void AddTrunks(JObject obj, Trunk trunk)
{
foreach (KeyValuePair<string, Trunk> kvp in trunkMap)
{
obj.Add(kvp.Key, ((trunk & kvp.Value) != Trunk.None) ? 1 : 0);
}
}
}
重要提示:
您可能想用
[JsonConverter(typeof(CarConverter))]
装饰Car
类,但不要这样做。如果您这样做,那么CarConverter
将无法正常工作:转换器将以递归方式调用自身,直到出现StackOverflowException
错误。(手动处理所有类属性的转换器不会有此问题。)您不能(也不应该)尝试通过单个属性转换器将多个属性组合成单个属性,您应该为包含该转换的类创建一个自定义转换器来处理该转换。@JeffMercado-我查看了一个自定义转换类,并对“全有或全无”方法的想法产生了兴趣。在本例中,它是一小部分特殊属性,其他所有属性都是纯JSON。您是否见过一个只选择性地处理特定属性的JsonConverter派生类型的示例?JObject的ReadJson和WriteJson用法是我所缺少的。我在查看文档时担心的是,一旦你走上自定义转换类的路线,你将无法处理所有事情。像这样使用ExtensionData就是我要做的。
static void Q18066528()
{
string json = @"{""df"":1,""dr"":0,""pf"":0,""pr"":1,""ft"":0,""rt"":1,
""make"":""Chevrolet"",""model"":""Corvette"",""year"":2013,""MSRP"":49600}";
JsonSerializerSettings settings = new JsonSerializerSettings
{
Converters = new List<JsonConverter> { new CarConverter() }
};
Car car = JsonConvert.DeserializeObject<Car>(json, settings);
Console.WriteLine("Model: " + car.Model);
Console.WriteLine("Year: " + car.Year);
Console.WriteLine("Doors: " + car.Doors);
Console.WriteLine("Trunks: " + car.Trunks);
string json2 = JsonConvert.SerializeObject(car, settings);
Console.WriteLine(json2);
}
Model: Corvette
Year: 2013
Doors: DriverSideFront, PassengerSideRear
Trunks: Rear
{"make":"Chevrolet","model":"Corvette","year":2013,"MSRP":49600.0,"df":1,"dr":0,
"pf":0,"pr":1,"ft":0,"rt":1}