How Deserialize {} to null

[LGinC]

there is a json string

{
  "mainInfo": {}
}

class code

public class TypeA 
{
  public MainInfo? MainInfo {get;set;}
}

public class MainInfo
{
  public string? Name {get;set;}
  public string? Address {get;set;}
}

and deserialize it JsonSerilizer.Deserialize<TypeA>(jsonStr), and result is

{
  "mainInfo": {
    "name": null,
    "address": null
  }
}

the result in my wish is

{
  "mainInfo": null
}

[LGinC]

I try to write JsonTypeInfoResolver

public class MyTypeResolverTypeResolver : DefaultJsonTypeInfoResolver
{
    public override JsonTypeInfo GetTypeInfo(Type type, JsonSerializerOptions options)
    {
        JsonTypeInfo typeInfo = base.GetTypeInfo(type, options);
        if (type == typeof(TypeA))
        {
            foreach (var property in typeInfo.Properties.Where(p => p.PropertyType == typeof(MainInfo)))
            {
                property
                .ShouldSerialize = (obj, value) =>  value is MainInfo v &&  (v.Name != null || v.Address != null);
            }
            
        }

        return base.GetTypeInfo(type, options);
    }
}

but it not work

[am11]

Something like https://dotnetfiddle.net/WyUEiW.

[LGinC]

thx