使用Newtonsoft Json.Net反序列化为IEnumerable类

Question

我有一个项目,目前正在使用Json.Net为Json反序列化类,如下所示:

public class Foo {
    public Guid FooGuid { get; set; }
    public string Name { get; set; }
    public List<Bar> Bars { get; set; }
}

public class Bar {
    public Guid BarGuid { get; set; }
    public string Description { get; set; }
}

到目前为止它工作正常.

为了使迭代更简单,我创建了Foo类实现IEnumerable<Bar>:

public class Foo : IEnumerable<Bar> {
    public Guid FooGuid { get; set; }
    public string Name { get; set; }
    public List<Bar> Bars { get; set; }

    public IEnumerator<Bar> GetEnumerator()
    {
        return Bars.GetEnumerator();
    }

    IEnumerator IEnumerable.GetEnumerator()
    {
        return GetEnumerator();
    }
}

public class Bar {
    public Guid BarGuid { get; set; }
    public string Description { get; set; }
}

但是它无法反序列化对象.该错误令人困惑,因为它说它不能反序列化FooGuid字段,但删除IEnumerable接口再次工作.

在模拟器或设备中的MonoTouch和MonoDroid环境中,问题是相同的.

有关如何使其工作的任何线索？

---

添加了重现此问题的代码:

public static class Tests {
    public static void SerializeAndDeserializeFoo() {
        // Serialize and deserialize Foo class
        var element = new Foo
        {
            FooGuid = Guid.NewGuid(),
            Name = "Foo name",
            Bars = new List<Bar> {
                new Bar { BarGuid = Guid.NewGuid(), Description = "Bar description" },
                new Bar { BarGuid = Guid.NewGuid(), Description = "Bar description" },
                new Bar { BarGuid = Guid.NewGuid(), Description = "Bar description" }
            }
        };

        var serializedObject = JsonConvert.SerializeObject(element);
        Console.WriteLine("Serialized Foo element: {0}", serializedObject);

        // Exception if Foo implements IEnumerable
        var deserializedObject = JsonConvert.DeserializeObject<Foo>(serializedObject);
        Console.WriteLine("Foo deserialization worked!");
    }

    public static void SerializeAndDeserializeEnumerableFoo() {
        // Serialize and deserialize Foo class
        var element = new EnumerableFoo
        {
            FooGuid = Guid.NewGuid(),
            Name = "Foo name",
            Bars = new List<Bar> {
                new Bar { BarGuid = Guid.NewGuid(), Description = "Bar description" },
                new Bar { BarGuid = Guid.NewGuid(), Description = "Bar description" },
                new Bar { BarGuid = Guid.NewGuid(), Description = "Bar description" }
            }
        };

        var serializedObject = JsonConvert.SerializeObject(element);
        Console.WriteLine("Serialized EnumerableFoo element: {0}", serializedObject);

        try {
            // Exception if Foo implements IEnumerable
            var deserializedObject = JsonConvert.DeserializeObject<EnumerableFoo>(serializedObject);
            Console.WriteLine("EnumerableFoo deserialization worked!");
        }
        catch (Exception e){
            Console.WriteLine("EnumerableFoo deserialization failed!");
            throw;
        }
    }
}

public class EnumerableFoo : IEnumerable<Bar> {
    public Guid FooGuid { get; set; }
    public string Name { get; set; }
    public List<Bar> Bars { get; set; }

    public IEnumerator<Bar> GetEnumerator()
    {
        return Bars.GetEnumerator();
    }

    IEnumerator IEnumerable.GetEnumerator()
    {
        return GetEnumerator();
    }
}

public class Foo {
    public Guid FooGuid { get; set; }
    public string Name { get; set; }
    public List<Bar> Bars { get; set; }
}

public class Bar {
    public Guid BarGuid { get; set; }
    public string Description { get; set; }
}

示例项目:https://www.dropbox.com/s/27i58aiz71dylkw/IEnumerableJson.zip

Answer 1

从Json.Net文档到:

IEnumerable,Lists和Arrays

.NET列表(从IEnumerable继承的类型)和.NET数组转换为JSON数组.由于JSON数组仅支持一系列值而不支持属性,因此.NET集合上声明的任何其他属性和字段都不会序列化.在不需要JSON数组的情况下,JsonObjectAttribute可以放在实现IEnumerable的.NET类型上,以强制将类型序列化为JSON对象.

换句话说,由于你的类实现IEnumerable<T>,Json.Net认为它是一个列表.要解决这个问题,只需使用[JsonObject]属性装饰您的类.这将迫使Json.Net将其序列化并反序列化为普通类,这是您在这种情况下所需的.

[JsonObject]
public class EnumerableFoo : IEnumerable<Bar>
{
    ...
}