When deserializing an object to a Dictionary
(JsonConvert.DeserializeObject<IDictionary<string,object>>(json)
) nested objects are deserialized to JObject
s. Is it possible to force nested objects to be deserialized to Dictionary
s?
I found a way to convert all nested objects to Dictionary<string,object>
by providing a CustomCreationConverter
implementation:
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()});
}
}
Documentation: CustomCreationConverter with Json.NET
I had a very similar but slightly more complex need when I ran across this Q. At first I thought maybe I could adapt the accepted answer, but that seemed a bit complicated and I ended up taking a different approach. I was attempting to put a modern JSON layer on top of a legacy C++ API. I'll spare you the details of that, and just say the requirements boil down to:
JSON objects become Dictionary<string,object>
.
JSON arrays become List<object>
.
JSON values become the corresponding primitive CLR values.
The objects and arrays can be infinitely nested.
I first deserialize the request string into a Newtonsoft JSON object and then call my method to convert in accordance with the above requirements:
var jsonObject = JsonConvert.DeserializeObject(requestString);
var apiRequest = ToApiRequest(jsonObject);
// call the legacy C++ API ...
Here is my method that converts to the structure the API expects:
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()}");
}
}
I hope that someone can find this approach useful.
Alternative/Update:
I needed to deserialize a dictionary of dictionaries of String
s and with current Json.NET (5.0) I did not had to create a CustomConverter, I just used (in VB.Net):
JsonConvert.DeserializeObject(Of IDictionary(Of String, IDictionary(Of String, String)))(jsonString)
Or, in C#:
JsonConvert.DeserializeObject<IDictionary<String, IDictionary<String, String>>(jsonString);
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With