c# - 反序列化泛型类型无法设置类型 T 的属性

Question

我在使用 Json.Net 将 JSON 字符串反序列化为通用类型时遇到了一些问题。

我遇到的问题是泛型类的属性被正确反序列化，在这种情况下，下面的 SomeStrings 属性将按预期填充，但 Data 属性保留为 null。

我希望有人能阐明我缺少的是什么，因为序列化相同的类型工作正常。

参见下面的类结构:

public class Foo
{
    public List<string> SomeStrings { get; protected set; } = new List<string>();

    protected Foo()
    {

    }
}

public class GenericFoo<TBar> : Foo
{
    public TBar Data { get; private set; }

    private GenericFoo() {}

    public GenericFoo(TBar data)
    {
        Data = data;
    }

    public GenericFoo(TBar data, params string[] someStrings) :this(data)
    {
        SomeStrings = someStrings.ToList();
    }

}

public class DataClass
{
    public int Id { get; set; }
}

我正在运行的代码:

var settings = new JsonSerializerSettings()
{
    ConstructorHandling = ConstructorHandling.AllowNonPublicDefaultConstructor
};

var response = new GenericFoo<DataClass>(new DataClass()
{
    Id = 10
}, "Test");

//serialises completely fine
var json = JsonConvert.SerializeObject(response, settings); 

//Produces JSON: {"Data":{"Id":10},"SomeStrings":["Test"]}

//all properties deserialised fine, Data left null
var obj = JsonConvert.DeserializeObject<GenericFoo<DataClass>>(json, settings); 

Answer 1

申请[JsonConstructor]构造函数的属性

Use the JsonConstructorAttribute to specify that a constructor should be used to create a class during deserialization.

public class GenericFoo<TBar> : Foo {
    public TBar Data { get; private set; }

    private GenericFoo() { }

    public GenericFoo(TBar data) {
        Data = data;
    }

    [JsonConstructor]
    public GenericFoo(TBar data, params string[] someStrings) : this(data) {
        SomeStrings = someStrings.ToList();
    }

}

我在反序列化时得到了想要的行为。即使没有设置

public class Program
{
    public static void Main()
    {
        var response = new GenericFoo<DataClass>(new DataClass()
        {Id = 10}, "Test");
        //serialises completely fine
        var json = JsonConvert.SerializeObject(response);

        var obj = JsonConvert.DeserializeObject<GenericFoo<DataClass>>(json);
        Console.WriteLine(obj.Data.Id); // Prints 10
    }
}

.Net Fiddle of running code.