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Using Newtonsoft JsonConvert to serialize and deserialize simple class

I'm trying to simply serialize and deserialize a simple class with JsonConvert.SerializeObject(obj) and JsonConvert.DeserializeObject(string).
I'm using this in a custom TypeConverter for a QueryParameter in .NET Web API Core 2.1.
But I'm getting very strange behavior. My class looks like this:
public class ListRequestDto {
public bool? WithCreator { get; set; }
public int? Skip { get; set; }
public int? Limit { get; set; }
}
And I'm trying to do the following:
var test = new ListRequestDto {
WithCreator = true,
Skip = 0,
Limit = 15
};
string ttt = JsonConvert.SerializeObject(test);
But I'm getting the following output:
"MyNameSpace.ListRequestDto"
If I try it the other way around:
string json = "{ WithCreator: true, Skip: 0, Limit: 15 }";
JsonConvert.DeserializeObject<ListRequestDto>(json);
I get the following exception:
Newtonsoft.Json.JsonSerializationException: "Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'MyNameSpace.ListRequestDto' because the type requires a JSON string value to deserialize correctly.
To fix this error either change the JSON to a JSON string value or change the deserialized type so that it is a normal .NET type (e.g. not a primitive type like integer, not a collection type like an array or List) that can be deserialized from a JSON object. JsonObjectAttribute can also be added to the type to force it to deserialize from a JSON object.
Path 'Skip', line 1, position 8."
I tried to remove the nullable fields (replacing them with regular primitives) but that resulted int he exact same error.
The strange thing is, that if I provide the same class as a body it works. And as far as I know Web API Core also uses the Newtonsoft Json Parser.

I do not know why it is necessary, but when I put [JsonObject] on my class it suddenly works.
The exception actually told me to do that, but I do not understand why it is necessary when in no documentation this is used in such a case.
So bascially doing the following solved the problem:
[JsonObject]
public class ListRequestDto {
public bool? WithCreator { get; set; }
public int? Skip { get; set; }
public int? Limit { get; set; }
}

Deserialize objects from array nested inside Json response

I'm trying to deserialize some objects nested inside a Json response using Newtonsoft.Json. I want to deserialize the following Jsons Term objects into a list. I have many Term objects in the Json response, so performance and compactness is important to me. I also would only like to define the Term class as I do not care about the other data for the time being.
I have a model defined for Term:
public class Term
{
public string Known { get; set; }
public string Word { get; set; }
}
My Json looks like this:
{
"myName":"Chris",
"mySpecies":"Cat",
"myTerms":
[
{
"Term":
{
"Known":"true",
"Word":"Meow"
}
},
{
"Term":
{
"Known":"false",
"Word":"Bark"
}
}
]
}
My C# deserializing code:
var response = await httpClient.GetAsync(uri);
string responseString = response.Content.ReadAsStringAsync().GetResults();
var searchTermList = JsonConvert.DeserializeObject<List<Term>>(responseString);
The problem/error I'm receiving is, not sure how I can get these terms from the json response:
{Newtonsoft.Json.JsonSerializationException: Cannot deserialize the current
JSON object (e.g. {"name":"value"}) into type
'System.Collections.Generic.List`1[CoreProject.Models.Term]' because
the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly.
To fix this error either change the JSON to a JSON array (e.g. [1,2,3]) or
change the deserialized type so that it is a normal .NET type (e.g. not a
primitive type like integer, not a collection type like an array or List<T>)
that can be deserialized from a JSON object. JsonObjectAttribute can also be
added to the type to force it to deserialize from a JSON object.
Any suggestions would be greatly appreciated :)

You are getting that error because you are trying to deserialize the JSON into a List<T> for some T (specifically Term), but the root JSON container is not an array, it is an object -- an unordered set of key/value pairs surrounded by { and } -- that contains a fairly deeply embedded collection of objects corresponding to your Term.
Given that, you could use http://json2csharp.com/ or Paste JSON as Classes to auto-generate a complete data model corresponding to your JSON, then deserialize to that model and select out the interesting portions.
If, however, you don't want to define a complete data model, you can selectively deserialize only the relevant portions by loading your JSON into an intermediate JToken hierarchy and then using
SelectTokens():
var root = JToken.Parse(responseString);
var searchTermList = root.SelectTokens("myTerms[*].Term")
.Select(t => t.ToObject<Term>())
.ToList();
Notes:
The query string "myTerms[*].Term" contains the JSONPath wildcard operator [*]. This operator matches all array elements under the parent element "myTerms".
Json.NET supports JSONPath syntax as documented in Querying JSON with JSONPath.
If the JSON is more complex than is shown in your question, you can use the JSONPath recursive descent operator ... instead to find Term objects at any level in the JSON object hierarchy, e.g.:
var searchTermList = root.SelectTokens("..Term")
.Select(t => t.ToObject<Term>())
.ToList();
Once the relevant JSON objects have been selected you can use Jtoken.ToObject<Term>() to deserialize each one to your final c# model.
Sample fiddle.

Give this a try
public class Term
{
public string Known { get; set; }
public string Word { get; set; }
}
public class Response
{
public List<TermWrapper> MyTerms { get; set; }
}
public class TermWrapper
{
public Term Term { get; set; }
}
...
var response = await httpClient.GetAsync(uri);
string responseString = response.Content.ReadAsStringAsync().GetResults();
var searchTermList = JsonConvert
.DeserializeObject<Response>(responseString)
.MyTerms
.Select(x => x.Term);
You have to consider the full structure of the JSON. You have an object with 3 properties. The one you are interested in is an Array of Objects, but the objects are not terms, they are objects with a property called "Term". That property itself is of type Term. By creating the classes with similar structure you can then pull all the necessary data out of the structure.

How to convert JSON Response to a List in C#?

This might be a basic question but I am stuck while converting a JSON Response to a List.
I am getting the JSON Response as,
{"data":[{"ID":"1","Name":"ABC"},{"ID":"2","Name":"DEF"}]}
Have defined a Class,
class Details
{
public List<Company> data { get; set; }
}
class Company
{
public string ID { get; set; }
public string Name { get; set; }
}
Have tried this for converting,
List<Details> obj=List<Details>)JsonConvert.DeserializeObject
(responseString, typeof(List<Details>));
But this returns an error, saying
Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'System.Collections.Generic.List`1[Client.Details]' because the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly.
To fix this error either change the JSON to a JSON array (e.g. [1,2,3]) or change the deserialized type so that it is a normal .NET type (e.g. not a primitive type like integer, not a collection type like an array or List) that can be deserialized from a JSON object. JsonObjectAttribute can also be added to the type to force it to deserialize from a JSON object.
Kindly help!

You don't have a List<Detail> defined in your JSON. Your JSON defines one Detail record, which itself has a list of companies.
Just deserialize using Details as the type, not List<Details> (or, if possible, make the JSON wrap the single detail record into a one item array).

You need to Deserialize like this:
var Jsonobject = JsonConvert.DeserializeObject<Details>(json);
using classes generated by json2csharp.com:
var Jsonobject = JsonConvert.DeserializeObject<RootObject>(json);
and your classes should be :
public class Datum
{
public string ID { get; set; }
public string Name { get; set; }
}
public class RootObject
{
public List<Datum> data { get; set; }
}
you can always use json2csharp.com to generate right classes for the json.

You can use JavaScriptDeserializer class
string json = #"{""data"":[{""ID"":""1"",""Name"":""ABC""},{""ID"":""2"",""Name"":""DEF""}]}";
Details details = new JavaScriptSerializer().Deserialize<Details>(json);
EDIT: yes, there's nothing wrong with OP's approach, and Servy's answer is correct. You should deserialize not as the List of objects but as the type that contains that List

How to convert a Json string to a class that has a list in Json.Net with C# when the json has an array one level deeper

I have a C# Application in which I am using Json.Net from Nuget.
I get a json from my server which I need to convert into a C# object and with a few modifications I will send it back to the server as json.
Here's my model in C# (which I got after converting the server xsd)
public class Tags
{
public List<Tag> tagData { get; set; }
}
public class Tag
{
public string name {get; set;}
}
Here's my JSON string that is obtained from the server and an attempt at conversion to my model
//Json string obtained from server (hardcoded here for simplicity)
string json = "{tagData: {tags : [ { name : \"John\"}, { name : \"Sherlock\"}]}}";
//An attempt at conversion
var output = JsonConvert.DeserializeObject<Tags>(json);
This is the exception I get with the above code
An unhandled exception of type 'Newtonsoft.Json.JsonSerializationException' occurred in Newtonsoft.Json.dll
Additional information: Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'System.Collections.Generic.List`1[jsonnetExample.Tag]' because the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly.
To fix this error either change the JSON to a JSON array (e.g. [1,2,3]) or change the deserialized type so that it is a normal .NET type (e.g. not a primitive type like integer, not a collection type like an array or List<T>) that can be deserialized from a JSON object. JsonObjectAttribute can also be added to the type to force it to deserialize from a JSON object.
Path 'tagData.tags', line 1, position 17.
After understanding the above message I tried the following 2 things in the hope of fixing it.
A.I tried putting a JsonProperty to my first model.
[JsonProperty(PropertyName = "tags")]
This didn't throw the exception anymore but the output tagData was null.
B. I modified my model as follows
public class Tags
{
public WrapTag tagData { get; set; }
}
public class WrapTag
{
public List<Tag> tags { get; set; }
}
public class Tag
{
public string name {get; set;}
}
This didn't throw any exception and populated the objects as expected. But Now I lost the one to one mapping between xsd(classes from the server) to my client model classes. Is it possible to get this deserialization working without the creation of the WrapTag class?
I would be very glad if someone can point me in the right direction.
Thanks in advance.

Here's one option, using JObject.Parse:
string json = "{tagData: {tags : [ { name : \"John\"}, { name : \"Sherlock\"}]}}";
List<Tag> tagList = JObject.Parse(json)["tagData"]["tags"].ToObject<List<Tag>>();
// or:
// List<Tag> tagList = JObject.Parse(json).SelectToken("tagData.tags")
// .ToObject<List<Tag>>();
Tags tags = new Tags { tagData = tagList };

Mass Transit unable to deserialize collections with exactly one element

I've got a Mass Transit message interface like this:
public interface IPerson
{
ICollection<PersonalName> Names { get; }
}
public class PersonalName
{
public string FamilyName { get; set; }
public string GivenName { get; set; }
public string SecondName { get; set; }
public string Use { get; set; }
}
And this works for serializing and deserializing the message using the JsonMessageSerializer. I can also serialize the message using the XmlMessageSerializer, and the result looks a bit like this:
<person>
<names>
<familyName>Simpson</familyName>
<givenName>Homer</givenName>
<secondName>Jay</secondName>
<use>Official</use>
</names>
<names>
<givenName>Homie</givenName>
<use>Nickname</use>
</names>
</person>
And I can deserialize just it if the collection is empty or if it has more than one element. However, if the collection contains exactly one element, when I go to deserialize it, I get this error:
Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'System.Collections.Generic.ICollection`1[MyNs.PersonalName]' because the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly.
To fix this error either change the JSON to a JSON array (e.g. [1,2,3]) or change the deserialized type so that it is a normal .NET type (e.g. not a primitive type like integer, not a collection type like an array or List<T>) that can be deserialized from a JSON object. JsonObjectAttribute can also be added to the type to force it to deserialize from a JSON object.
Path 'person.names.familyName'.
I can fix this by using an array or List<T>, but I'd really like to avoid doing that. Is there a way to get Mass Transit's XmlMessageSerializer to deserialize ICollection<T> types? Since Mass Transit uses Json.NET for serialization under the hood (even for XML), I'm hoping there's some way of annotating the type so that it can accept an ICollection<T>.

Instead of trying to deserialize:
{"FamilyName":"Smith","GivenName":"John"}
you have to pass in an array to deserialize:
[{"FamilyName":"Smith","GivenName":"John"}]