Newtonsoft JsonConvert DeserializeObject cannot ignore Default Value from entity err? - json.net

Question

Here is the Sample code:
I have a TargetEntity which contains a bool list, by default, it is set to a seven elements list of true value.
What I am trying to do is deserialize from JSON, which contains a list of seven false value.
However, when deserializing it, it seems constructed a list of 14 values, which included the default ones and attached the deserialized from the JSON like this { true, true, true, true, true, true, true, false, false, false, false, false, false, false }
What is wrong here?
using Newtonsoft.Json;
using System.Collections.Generic;
public class Program
{
public static void Main()
{
var _entityList = JsonConvert.DeserializeObject<List<TargetEntity>>(
"[{\"BoolsList\": [false,false,false,false,false,false,false]}]",
new JsonSerializerSettings { DefaultValueHandling = DefaultValueHandling.Ignore });
Console.WriteLine("List size: " + _entityList[0].BoolsList.Count);
for(int i = 0; i < _entityList[0].BoolsList.Count; i++)
{
Console.WriteLine($"List element {i}: " + _entityList[0].BoolsList[i]);
}
}
public class TargetEntity
{
public List<bool> BoolsList { get; set; } = new List<bool> { true, true, true, true, true, true, true };
}
}
There is C# fiddle like for this code: https://dotnetfiddle.net/VMIXeg

Answer 1

It is a very interesting behavior, related with the serializer settings and the way the new object is constructed and populated :)
If what you want is to replace the default list and keep on using Newtonsoft.Json, you can replace the settings
new JsonSerializerSettings { DefaultValueHandling = DefaultValueHandling.Ignore }
by
new JsonSerializerSettings { ObjectCreationHandling = ObjectCreationHandling.Replace }
Depending on your .NET version, you may also use System.Text.Json:
using System;
using System.Collections.Generic;
using System.Text.Json;
public class Program
{
public static void Main()
{
var _entityList = JsonSerializer.Deserialize<List<TargetEntity>>("[{\"BoolsList\": [false,false,false,false,false,false,false]}]");
...
}
...
}