使用JSON.net (JsonConvert.SerializeObject或JsonConvert.DeSerializeObject)为缺少的复杂属性设置默认值

using Newtonsoft.Json;

public class Person
{
    public string Name { get; set; }
    public int Age { get; set; }
    public Address Address { get; set; }
}

public class Address
{
    public string Street { get; set; }
    public string City { get; set; }
    public string Country { get; set; }
}

public class Program
{
    public static void Main()
    {
        Person person = new Person
        {
            Name = "John",
            Age = 30
        };

        string json = JsonConvert.SerializeObject(person, new JsonSerializerSettings
        {
            DefaultValueHandling = DefaultValueHandling.Populate
        });

        Console.WriteLine(json);
    }
}