De-Serialize JSON序列化对象的列表

Question

我正在尝试去除 List<string>，实际上是一个 List<myClass>，其对象已被序列化。示例：

static void Main(string[] args)
{
    List<MyThirdClass> myThirdClass = new List<MyThirdClass>(new[] { new MyThirdClass { RoleId = 123, RoleName = "123" }, new MyThirdClass { RoleId = 234, RoleName = "234" } });
    List<MySecondSerializedClass> mySecondSerializedClass = new List<MySecondSerializedClass>();
    foreach (MyThirdClass thirdClass in myThirdClass)
    {
        MySecondSerializedClass secondClass = new MySecondSerializedClass { Roles = new List<string>() };
        foreach (MyThirdClass tClass in myThirdClass)
        {
            secondClass.Roles.Add(JsonConvert.SerializeObject(tClass));
        }
        mySecondSerializedClass.Add(secondClass);
    }
    MyFirstSerializedClass firstClass = new MyFirstSerializedClass
    {
        Id = 1,
        Name = "1",
        Roles = mySecondSerializedClass
    };
    string serializedFirstClass = JsonConvert.SerializeObject(firstClass, Formatting.Indented);
    MyFirstNonSerializedClass nonSerializedFirstClass = JsonConvert.DeserializeObject<MyFirstNonSerializedClass>(serializedFirstClass);
}
public class MyFirstSerializedClass
{
    public int Id { get; set; }
    public string Name { get; set; }
    public List<MySecondSerializedClass> Roles { get; set; }
}
public class MyFirstNonSerializedClass
{
    public int Id { get; set; }
    public string Name { get; set; }
    public List<MySecondNonSerializedClass> Roles { get; set; }
}
public class MySecondSerializedClass
{
    public List<string> Roles { get; set; }
}
public class MySecondNonSerializedClass
{
    public List<MyThirdClass> Roles { get; set; }
}
public class MyThirdClass
{
    public int RoleId { get; set; }
    public string RoleName { get; set; }
}

serializedFirstClass返回这样的json：

{
  "Id": 1,
  "Name": "1",
  "Roles": [
    {
      "Roles": [
        "{"RoleId":123,"RoleName":"123"}",
        "{"RoleId":234,"RoleName":"234"}"
      ]
    },
    {
      "Roles": [
        "{"RoleId":123,"RoleName":"123"}",
        "{"RoleId":234,"RoleName":"234"}"
      ]
    }
  ]
}

并试图去序列化它给消息带来了一个例外：

错误转换值" {" roalid"：123，" rolename"：" 123"}" type'soleleapplication1.program mythirdClass'。路径'角色[0]。rol [0]'，第7行，位置47。

我做错了什么，或者有任何方法将myfirstserializedClass递归归为myFirstnonSerializedClass？

Answer 1

您可以使用一组类和JsonConverter的可选CC_4来完成此操作作为MyThirdClass的实例。将转换器添加到jsonserializertings.converters时，当您要序列化或逐序将类作为嵌入式字符串化时；将其保留为序列化作为对象。

因此：

public class MyFirstClass
{
    public int Id { get; set; }
    public string Name { get; set; }
    public List<MySecondClass> Roles { get; set; }
}
public class MySecondClass
{
    public List<MyThirdClass> Roles { get; set; }
}
public class MyThirdClass
{
    public int RoleId { get; set; }
    public string RoleName { get; set; }
}
public sealed class MyThirdClassStringConverter : JsonConverter
{
    readonly JsonSerializerSettings settings;
    public MyThirdClassStringConverter() : this(null) { }
    public MyThirdClassStringConverter(JsonSerializerSettings settings)
    {
        this.settings = settings;
    }
    JsonSerializer GetInnerSerializer()
    {
        var innerSerializer = JsonSerializer.CreateDefault(settings);
        for (int i = innerSerializer.Converters.Count - 1; i >= 0; i--)
            if (innerSerializer.Converters[i] is MyThirdClassStringConverter)
                innerSerializer.Converters.RemoveAt(i);
        return innerSerializer;
    }
    public override bool CanConvert(Type objectType)
    {
        return typeof(MyThirdClass).IsAssignableFrom(objectType);
    }
    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        if (reader.TokenType == JsonToken.Null)
            return null;
        var innerSerializer = GetInnerSerializer();
        if (reader.TokenType == JsonToken.String)
        {
            var s = reader.Value.ToString();
            using (var innerReader = new StringReader(s))
                return innerSerializer.Deserialize(innerReader, objectType);
        }
        else
        {
            return innerSerializer.Deserialize(reader, objectType);
        }
    }
    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        var innerSerializer = GetInnerSerializer();
        var sb = new StringBuilder();
        using (var innerWriter = new StringWriter(sb))
            innerSerializer.Serialize(innerWriter, value);
        writer.WriteValue(sb.ToString());
    }
}

然后，使用如下：

var stringSettings = new JsonSerializerSettings { Converters = new[] { new MyThirdClassStringConverter() } };
// Deserialize JSON where MyThirdClass objects are embedded strings
var root = JsonConvert.DeserializeObject<MyFirstClass>(stringJson, stringSettings);
// Re-serialize to JSON where MyThirdClass objects are objects
var newNonStringJson = JsonConvert.SerializeObject(root, Formatting.Indented);
// Re-serialize to JSON where MyThirdClass objects are embedded strings
var newStringJson = JsonConvert.SerializeObject(root, Formatting.Indented, stringSettings);

请注意，将使用[JsonConverter(typeof(MyThirdClassStringConverter))]直接将转换器应用于MyThirdClass，因为将导致无限递归。转换器的ReadJson()方法测试以查看当前令牌是字符串还是对象并相应地调整，因此可以以两种格式的JSON进行序列化。

示例小提琴。

Answer 2

您期望将string降低到MyThirdClass结构。

实际上它们并不相同。

字符串列表将被序列化

" " SomeProperty "：" SomePropertyValue " " ，
" " SomeProperty2 "：" SomePropertyValue " "

castulclass 的列表将为

" SomeProperty"：" SomePropertyValue"，
" SomeProperty2"：" SomeProperty2Value"

Answer 3

序列化时，您将MyThirdClass转换为字符串。当值时，您需要反向转换。添加从字符串到您的类型的隐式转换。

public static implicit operator MyThirdClass(string s)
{
  // when serializing indented =>
  // return JsonConvert.DeserializeObject<B3>(s, new JsonSerializerSettings() { Formatting = Formatting.Indented});
  // otherwise
  return JsonConvert.DeserializeObject<B3>(s);
}