.NET BCL中是否有现成的Json Serialization助手类？

using System;
using System.Text.Json;
using Newtonsoft.Json;

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

public class Program
{
    public static void Main()
    {
        // 使用System.Text.Json序列化
        var person = new Person { Name = "John", Age = 30 };
        var json = JsonSerializer.Serialize(person);
        Console.WriteLine(json);

        // 使用System.Text.Json反序列化
        var jsonString = "{\"Name\":\"John\",\"Age\":30}";
        var deserializedPerson = JsonSerializer.Deserialize<Person>(jsonString);
        Console.WriteLine(deserializedPerson.Name);
        Console.WriteLine(deserializedPerson.Age);

        // 使用Newtonsoft.Json序列化
        var newtonsoftJson = JsonConvert.SerializeObject(person);
        Console.WriteLine(newtonsoftJson);

        // 使用Newtonsoft.Json反序列化
        var newtonsoftJsonString = "{\"Name\":\"John\",\"Age\":30}";
        var newtonsoftDeserializedPerson = JsonConvert.DeserializeObject<Person>(newtonsoftJsonString);
        Console.WriteLine(newtonsoftDeserializedPerson.Name);
        Console.WriteLine(newtonsoftDeserializedPerson.Age);
    }
}