处理JSON.net中的引用循环

Question

我希望将List<Item>项目的collection()序列化为JSON.

这些项目的集合Connection提供了从Item一秒到一秒的连接信息Item.并且由于连接对象具有对项的引用,因此它使其成为无限循环.

我的问题是,在第二次序列化对象时,有一种方法可以跳过连接集的序列化.

我已经尝试过继承JsonConverter和编写自定义WriteJson()方法之类的东西但是从那里开始我是否应该写出数组.

我也尝试过使用自定义的ContractResolver,但效果不佳.

类

public class Item
{
    private static int _lastID = 0;

    public Item()
    {
        ID = ++_lastID;
        Connections = new List<Connection>();
    }


    public int ID { get; set; }

    public string Name { get; set; }

    public string Prop1 { get; set; }

    public string Prop2 { get; set; }

    public List<Connection> Connections { get; set; }

}



public class Connection
{
    private Connection(ConnectionType type, Item source, Item target)
    {
        if (type == ConnectionType.None)
            throw new ArgumentException();
        if (source == null)
            throw new ArgumentNullException("source");
        if (target == null)
            throw new ArgumentNullException("target");

        Type = type;
        Source = source;
        Target = target;
    }


    public ConnectionType Type { get; set; }

    public Item Source { get; set; }

    public Item Target { get; set; }


    public static void Connect(ConnectionType type, Item source, Item target)
    {
        var conn = new Connection(type, source, target);
        source.Connections.Add(conn);
        target.Connections.Add(conn);
    }
}

通缉结果:

[
    {
        "id": 1,
        "name": "Item #1",
        "prop1": "val1",
        "prop2": "val2",
        "connections": {
            "type": "ConnType",
            "source": {
                "id": 1,
                "name": "Item #1",
                "prop1": "val1",
                "prop2": "val2"
                // no connections array
            },
            "target": {
                "id": 2,
                "name": "Item #2",
                "prop1": "val1",
                "prop2": "val2"
                // no connections array
            }
        }
    },
    {
        "id": 2,
        "name": "Item #2",
        "prop1": "val1",
        "prop2": "val2",
        "connections": {
            "type": "ConnType",
            "source": {
                "id": 1,
                "name": "Item #1",
                "prop1": "val1",
                "prop2": "val2"
                // no connections array
            },
            "target": {
                "id": 2,
                "name": "Item #2",
                "prop1": "val1",
                "prop2": "val2"
                // no connections array
            }
        }
    }
]

编辑:

C#

var settings = new JsonSerializerSettings
    {
        ContractResolver = new CamelCasePropertyNamesContractResolver(),
        ReferenceLoopHandling = ReferenceLoopHandling.Ignore,
        Formatting = Formatting.Indented
    };
settings.Converters.Add(new StringEnumConverter());
var json = JsonConvert.SerializeObject(collection, settings);

Answer 1

您可以引入一个新类，例如 ，而不是声明Source和Targetas 的类型，它将包含 class 的所有字段（属性除外）。ItemItemClassItemConnections

public class ItemClass
{
    public int ID { get; set; }

    public string Name { get; set; }

    public string Prop1 { get; set; }

    public string Prop2 { get; set; }
}

public class Connection
{
    // ...

    public ConnectionType Type { get; set; }

    public ItemClass Source { get; set; }

    public ItemClass Target { get; set; }

    // ...
}

现在，您将需要相应地填充新类型实例的开销ItemClass。