Question

到目前为止，我已经使用Microsoft的DataContractJsonSerializer将我的业务对象序列化和反序列化为格式化为JSON的数据传输对象（DTO）。 DTO标有DataContract属性。一个小例子：

[DataContract(Name = "Geometry", Namespace = "myContract.com/dto")]
[KnownType(typeof(Point))]
[KnownType(typeof(Line))]
public class Geometry
{
}

[DataContract(Name = "Point", Namespace = "myContract.com/dto")]
public class Point : Geometry
{
    [DataMember(Name = "x")]
    public double X { get; set; }

    [DataMember(Name = "y")]
    public double Y { get; set; }
}

[DataContract(Name = "Line", Namespace = "myContract.com/dto")]
public class Line: Geometry
{
    [DataMember(Name = "start")]
    public Point Start { get; set; }

    [DataMember(Name = "end")]
    public Point End { get; set; }
}

这被序列化为：

"geometry":{"__type":"Point:myContract.com/dto","x":23133.75569999963,"y":21582.385849999264}

由于性能问题，我改用了Newtonsoft Json.NET。使用它时，JSON字符串如下所示：

"geometry":{"$type":"A.B.C.Point, A.B.C","x":23133.75569999963,"y":21582.385849999264}

是否有可能使用“__type”和契约名称空间而不是“$ type”和类组装组合将使用Json.NET的对象序列化为符合Microsoft的JSON字符串？我正在使用.NET 3.5。

提前致谢！

Answer 1

不幸的是，似乎无法调整属性名称，因为它在内部 JsonTypeReflector.cs class中声明为：

public const string TypePropertyName = "$type";

注意：另一方面，可以自定义类型属性值， SerializationBinder Class旨在实现此目的，this example演示了如何指定自定义类型属性值。

我建议使用以下解决方案来编写自定义类型属性。首先，我们需要引入具有type属性的基本实体类（或修改Geometry类），如下所示

[DataContract(Name = "Entity", Namespace = "myContract.com/dto")]
public abstract class Entity
{
    [DataMember(Name = "__type", Order = 0)]
    public string EntityTypeName
    {

        get
        {
            var typeName = GetType().Name;
            if (Attribute.IsDefined(GetType(), typeof(DataContractAttribute)))
            {
                var attribute = GetType().GetCustomAttributes(typeof(DataContractAttribute), true).FirstOrDefault() as DataContractAttribute;
                if (attribute != null) typeName = typeName + ":" + attribute.Namespace;
            }
            return typeName;
        }
    }
}

然后修改Geometry class：

[DataContract(Name = "Geometry", Namespace = "myContract.com/dto")]
[KnownType(typeof(Point))]
[KnownType(typeof(Line))]
public class Geometry : Entity
{
}

最后一步，将JsonSerializerSettings.TypeNameHandling设置为TypeNameHandling.None，以便反序列化程序跳过$type属性的呈现。

示例

var point = new Point { X = 23133.75569999963, Y = 21582.385849999264 }; var jsonPoint = JsonConvert.SerializeObject(point, new JsonSerializerSettings { TypeNameHandling = TypeNameHandling.None, //do not write type property(!) }); Console.WriteLine(jsonPoint);

<强>结果

{\"__type\":\"Point:myContract.com/dto\",\"x\":23133.75569999963,\"y\":21582.385849999264}

<强> P.S。

您还可以使用DataMember.Order指定订单，如下所示：

[DataContract(Name = "Point", Namespace = "myContract.com/dto")] public class Point : Geometry { [DataMember(Name = "x",Order = 1)] public double X { get; set; } [DataMember(Name = "y", Order = 2)] public double Y { get; set; } } [DataContract(Name = "Line", Namespace = "myContract.com/dto")] public class Line : Geometry { [DataMember(Name = "start", Order = 1)] public Point Start { get; set; } [DataMember(Name = "end", Order = 2)] public Point End { get; set; } }

（De-）序列化类似于Microsoft的已知类型

1 个答案: