当将一个对象反序列化为一个Dictionary
(JsonConvert.DeserializeObject<IDictionary<string,object>>(json)
)时,嵌套对象会被反序列化为 JObject
。是否有可能强制嵌套对象被反序列化为 Dictionary
?
当将一个对象反序列化为一个Dictionary
(JsonConvert.DeserializeObject<IDictionary<string,object>>(json)
)时,嵌套对象会被反序列化为 JObject
。是否有可能强制嵌套对象被反序列化为 Dictionary
?
我发现一种方法可以通过提供一个CustomCreationConverter
实现,将所有嵌套对象转换为Dictionary<string,object>
:
class MyConverter : CustomCreationConverter<IDictionary<string, object>>
{
public override IDictionary<string, object> Create(Type objectType)
{
return new Dictionary<string, object>();
}
public override bool CanConvert(Type objectType)
{
// in addition to handling IDictionary<string, object>
// we want to handle the deserialization of dict value
// which is of type object
return objectType == typeof(object) || base.CanConvert(objectType);
}
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
if (reader.TokenType == JsonToken.StartObject
|| reader.TokenType == JsonToken.Null)
return base.ReadJson(reader, objectType, existingValue, serializer);
// if the next token is not an object
// then fall back on standard deserializer (strings, numbers etc.)
return serializer.Deserialize(reader);
}
}
class Program
{
static void Main(string[] args)
{
var json = File.ReadAllText(@"c:\test.json");
var obj = JsonConvert.DeserializeObject<IDictionary<string, object>>(
json, new JsonConverter[] {new MyConverter()});
}
}
JSON对象变成Dictionary<string,object>
。
JSON数组变成List<object>
。
JSON值变成相应的基元CLR值。
对象和数组可以无限嵌套。
我首先将请求字符串反序列化为Newtonsoft JSON对象,然后调用我的方法按照上述要求进行转换:
var jsonObject = JsonConvert.DeserializeObject(requestString);
var apiRequest = ToApiRequest(jsonObject);
// call the legacy C++ API ...
private static object ToApiRequest(object requestObject)
{
switch (requestObject)
{
case JObject jObject: // objects become Dictionary<string,object>
return ((IEnumerable<KeyValuePair<string, JToken>>) jObject).ToDictionary(j => j.Key, j => ToApiRequest(j.Value));
case JArray jArray: // arrays become List<object>
return jArray.Select(ToApiRequest).ToList();
case JValue jValue: // values just become the value
return jValue.Value;
default: // don't know what to do here
throw new Exception($"Unsupported type: {requestObject.GetType()}");
}
}
我希望有人可以发现这种方法有用。
@AlexD的被接受的解决方案如果json中有一个数组,它的工作并不理想。它返回一个JObject
的JArray
而不是一个List<Dictionary<string, object>>
这可以通过修改ReadJson()方法来解决:
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
if (reader.TokenType == JsonToken.StartObject || reader.TokenType == JsonToken.Null)
return base.ReadJson(reader, objectType, existingValue, serializer);
//if it's an array serialize it as a list of dictionaries
if(reader.TokenType == JsonToken.ArrayStart)
return serializer.Deserialize(reader, typeof(List<Dictionary<string, object>>));
// if the next token is not an object
// then fall back on standard deserializer (strings, numbers etc.)
return serializer.Deserialize(reader);
}
备选方案/更新:
我需要反序列化一个由String
字典组成的字典,使用当前的Json.NET(5.0),我不需要创建CustomConverter,我只需使用以下代码(在VB.Net中):
JsonConvert.DeserializeObject(Of IDictionary(Of String, IDictionary(Of String, String)))(jsonString)
或者,使用C#:
JsonConvert.DeserializeObject<IDictionary<String, IDictionary<String, String>>(jsonString);
//does NOT work (newtonDeserialized does not have the same data in the nested Dictionaries as in object):
var newtonSerialized = Newtonsoft.Json.JsonConvert.SerializeObject(object);
var newtonDeserialized = Newtonsoft.Json.JsonConvert.DeserializeObject<WaitlistResponse>(newtonSerialized);
//Works (netDeserialized have the same data in the nested Directories as in object):
var netSerialized = System.Text.Json.JsonSerializer.Serialize(object);
var netDeserialized = System.Text.Json.JsonSerializer.Deserialize<WaitlistResponse>(netSerialized);
在我的情况下,并非所有都是嵌套字典。我还有一个由基本类型键值对构成的数组,当该数组的对象不是字典时,会抛出异常。
因此,根据Phillip S的答案,我想到了以下解决方案:
public override object? ReadJson(JsonReader reader, Type objectType, object? existingValue,
JsonSerializer serializer)
{
if (reader.TokenType == JsonToken.StartObject || reader.TokenType == JsonToken.Null)
return base.ReadJson(reader, objectType, existingValue, serializer);
//if it's an array serialize it as a list of dictionaries
if (reader.TokenType == JsonToken.StartArray)
{
return serializer.Deserialize(reader, typeof(List<object>)); // instead of List<Dictionary<string, object>>
}
// if the next token is not an object
// then fall back on standard deserializer (strings, numbers etc.)
return serializer.Deserialize(reader);
}
首先,您需要将字典值序列化。
var settings = new JsonSerializerSettings { TypeNameHandling= TypeNameHandling.All };
var serializeValues = JsonConvert.SerializeObject(nestedDictionaryValues, settings);
//After serialize using deserialize using the same TypeNameHandling.
var deserializeValues = JsonConvert.DeserializeObject(serializeValues, settings);