使用 JSON.NET 将递归 JSON 反序列化为 C#

Question

我们正在使用jQuery Querybuilder plugin 为我们应用程序的用户创建一个动态过滤组件：

最有趣的功能之一是过滤器集的序列化能力，如下所示：

{
 "condition": "AND",
  "rules": [
  {
   "id": "filterGroup1",
   "field": "filterGroup1",
   "type": "string",
   "input": "select",
   "operator": "contains",
   "value": "1"
 },
 {
   "id": "filterGroup2",
   "field": "filterGroup2",
   "type": "string",
   "input": "select",
   "operator": "contains",
   "value": "3"
 },
 {
   "condition": "OR",
   "rules": [
     {
      "id": "filterGroup1",
      "field": "filterGroup1",
      "type": "string",
      "input": "select",
      "operator": "contains",
      "value": "1"
    }
  ]
}
]
}

您可能注意到，数据是递归的：第三个节点与根节点具有相同的类型。在将其反序列化到服务器时，这给了我一些问题。目前我有这个：

public class QueryBuilderFilter
{       
    public string Condition { get; set; }
    public IEnumerable<Rule> Rules { get; set; }
}

 public class Rule
{
    public string Id { get; set; }
    public string Field { get; set; }
    public string Type { get; set; }
    public string Input { get; set; }
    public string Operator { get; set; }
    public string Value { get; set; }

    public IEnumerable<QueryBuilderFilter> Filters { get; set; }
}

这就是我所说的：

 JsonSerializerSettings jsonSettings = new JsonSerializerSettings
        {
            TypeNameHandling = TypeNameHandling.All,
            TypeNameAssemblyFormat = FormatterAssemblyStyle.Full,
            Error = (sender, eventArgs) =>
            {
                eventArgs.ErrorContext.Handled = true;
            }
        };

QueryBuilderFilter deserialized = JsonConvert.DeserializeObject<QueryBuilderFilter>(filtering, jsonSettings );

在 IEnumerable 属性完美之前的一切，这意味着除此属性之外的所有数据都已水合。但是，第三个节点返回 null：

该节点应该对应于子项，但我无法找到正确或干净的方法来执行此操作。不使用类型并手动解析可能是一种选择，但这听起来像是一个非常密集且昂贵的解决方案，而我相信应该有更简单的解决方案。如果我预先知道项目的数量，这不会是一个真正的问题，但是控件允许无限的查询构建，所以我需要能够动态地处理它。

有什么建议吗？

Answer 1

根据你的 JSON，你可以试试这个模型吗：

public class Rule
{
  public string Id { get; set; }
  public string Field { get; set; }
  public string Type { get; set; }
  public string Input { get; set; }
  public string Operator { get; set; }
  public string Value { get; set; }
  public string Condition { get; set; }
  public IEnumerable<Rule> Rules { get; set; }
}

这是你用 C# 翻译的 JSON 模型：

var filter = new Rule
{
    Condition = "AND",
    Rules = new List<Rule> {
        new Rule 
        {
            Id = "filterGroup1",
            Field = "filterGroup1",
            Type = "string",
            Input = "select",
            Operator = "contains",
            Value = "1"
        },
        new Rule 
        {
            Id = "filterGroup2",
            Field = "filterGroup2",
            Type = "string",
            Input = "select",
            Operator = "contains",
            Value = "3"
        },
        new Rule
        {
            Condition = "OR",
            Rules = new List<Rule> {
                new Rule 
                {
                    Id = "filterGroup1",
                    Field = "filterGroup1",
                    Type = "string",
                    Input = "select",
                    Operator = "contains",
                    Value = "1"
                }
            }
        }
    }
}