Json.NET 不反序列化嵌套对象

Question

我正在尝试使用 Json.NET 来序列化和反序列化jsTree的树结构。

以下是类定义：

private class Metadata
    {
        [JsonProperty(PropertyName = "nodeType")]
        public NodeType NodeType;
        [JsonProperty(PropertyName = "typeDepth")]
        public int TypeDepth;
    }
    private class TreeNode
    {
        [JsonProperty(PropertyName = "data")]
        public String Title;
        [JsonIgnore]
        public NodeType NodeType;
        [JsonIgnore] 
        public int TypeDepth;
        [JsonProperty(PropertyName = "children", NullValueHandling = NullValueHandling.Ignore)]
        public List<TreeNode> Children;
        [JsonProperty(PropertyName = "metadata")]
        public Metadata Metadata
        {
            get
            {
                return new Metadata() {NodeType = NodeType, TypeDepth = TypeDepth};
            }
            set { 
                TypeDepth = value.TypeDepth;
                NodeType = value.NodeType;
            }
        }
        private ItemGroup _itemGroup;
        [JsonIgnore]
        public ItemGroup ItemGroup
        {
            get
            {
                if(this.NodeType != NodeType.ItemGroup)
                    throw new InvalidDataException();
                return _itemGroup;
            }
            set { _itemGroup = value; }
        }
    }

下面是一些示例 JSON：

[{
"data":"Strands",
"attr":{"class":""},
"state":"open",
"metadata":{
    "nodeType":3,
    "typeDepth":0},
"children":[{
    "data":"Math",
    "attr":{"class":"","rel":"itemGroup"},
    "state":"open",
    "metadata":{
        "nodeType":1,
        "typeDepth":0},
    "children":[{
        "data":"Subjects",
        "attr":{"class":""},
        "state":"open",
        "metadata":{"nodeType":3,"typeDepth":1},
        "children":[{
            "data":"Algebra 1",
            "attr":{"class":"","rel":"itemGroup"},
            "state":"open",
            "metadata":{
                "nodeType":1,
                "typeDepth":1},
            "children":[{
                "data":"Clusters",
                "attr":{"class":""},
                "state":"open",
                "metadata":{
                    "nodeType":3,
                    "typeDepth":2},
                "children":[{
                    "data":"Factoring",
                    "attr":{"rel":"itemGroup"},
                    "metadata":{
                        "nodeType":1,
                        "typeDepth":2}},
                    {"data":"Substitution",
                    "attr":{"class":"","rel":"itemGroup"},
                    "metadata":{"nodeType":1,"typeDepth":2}}]}]}]}]}]}]

我尝试像这样反序列化：List<TreeNode> tree = (List<TreeNode>)JsonConvert.DeserializeObject(form["treeJson"], typeof (List<TreeNode>));

树结构已正确反序列化，但所有节点都没有元数据。

有人看到这里出了什么问题吗？

谢谢！

Answer 1

当我将Metadata属性更改为

[JsonProperty(PropertyName = "metadata")]
public Metadata Metadata { get; set; }

它似乎工作正常

var tree = JsonConvert.DeserializeObject<List<TreeNode>>(jsonstring);

将其实现为的任何原因

[JsonProperty(PropertyName = "metadata")]
public Metadata Metadata
{
    get
    {
        return new Metadata() {NodeType = NodeType, TypeDepth = TypeDepth};
    }
    set { 
          TypeDepth = value.TypeDepth;
           NodeType = value.NodeType;
    }
}

？

Answer 2

类元数据是私有的。 据我所知，这将阻止 Json 序列化程序访问它;因此，它将保留属性值 null;