How can I change property names when serializing with Json.net?
C#Serializationjson.netC# Problem Overview
I have some data in a C# DataSet object. I can serialize it right now using a Json.net converter like this
DataSet data = new DataSet();
// do some work here to populate 'data'
string output = JsonConvert.SerializeObject(data);
However, this uses the property names from data
when printing to the .json file. I would like to change the property names to be something different (say, change 'foo' to 'bar').
In the Json.net documentation, under 'Serializing and Deserializing JSON' → 'Serialization Attributes' it says "JsonPropertyAttribute... allows the name to be customized". But there is no example. Does anyone know how to use a JsonPropertyAttribute to change the property name to something else?
(Direct link to documentation)
Json.net's documentation seems to be sparse. If you have a great example I'll try to get it added to the official documentation. Thanks!
C# Solutions
Solution 1 - C#
You could decorate the property you wish controlling its name with the [JsonProperty]
attribute which allows you to specify a different name:
using Newtonsoft.Json;
// ...
[JsonProperty(PropertyName = "FooBar")]
public string Foo { get; set; }
Documentation: Serialization Attributes
Solution 2 - C#
If you don't have access to the classes to change the properties, or don't want to always use the same rename property, renaming can also be done by creating a custom resolver.
For example, if you have a class called MyCustomObject
, that has a property called LongPropertyName
, you can use a custom resolver like this…
public class CustomDataContractResolver : DefaultContractResolver
{
public static readonly CustomDataContractResolver Instance = new CustomDataContractResolver ();
protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
{
var property = base.CreateProperty(member, memberSerialization);
if (property.DeclaringType == typeof(MyCustomObject))
{
if (property.PropertyName.Equals("LongPropertyName", StringComparison.OrdinalIgnoreCase))
{
property.PropertyName = "Short";
}
}
return property;
}
}
Then call for serialization and supply the resolver:
var result = JsonConvert.SerializeObject(myCustomObjectInstance,
new JsonSerializerSettings { ContractResolver = CustomDataContractResolver.Instance });
And the result will be shortened to {"Short":"prop value"} instead of {"LongPropertyName":"prop value"}
More info on custom resolvers here
Solution 3 - C#
There is still another way to do it, which is using a particular NamingStrategy, which can be applied to a class or a property by decorating them with [JSonObject]
or [JsonProperty]
.
There are predefined naming strategies like CamelCaseNamingStrategy
, but you can implement your own ones.
The implementation of different naming strategies can be found here: https://github.com/JamesNK/Newtonsoft.Json/tree/master/Src/Newtonsoft.Json/Serialization