117笔记问答在C#中，使用Newtonsoft.Json处理循环引用时，可以通过设置PreserveObjectReferences属性为true来避免序列化时的循环引用问题。这样，当对象之间存在循环引用时，Newtonsoft.Json会保留对已序列化对象的引用，而不是陷入无限递归。
以下是一个简单的示例，说明如何使用Newtonsoft.Json处理循环引用：
首先，创建一个包含循环引用的类：
using System.Collections.Generic;
public class Person
{
public int Id { get; set; }
public string Name { get; set; }
public Address Address { get; set; }
}
public class Address
{
public int Id { get; set; }
public string Street { get; set; }
public Person Person { get; set; }
}
在这个例子中，Person类有一个Address属性，而Address类有一个Person属性，形成了循环引用。
接下来，使用Newtonsoft.Json序列化和反序列化这个循环引用：
using Newtonsoft.Json;
using System;
class Program
{
static void Main()
{
// 创建循环引用的对象
Person person = new Person { Id = 1, Name = "John", Address = new Address { Id = 2, Street = "123 Main St", Person = person } };
// 设置PreserveObjectReferences为true以处理循环引用
JsonSerializerSettings settings = new JsonSerializerSettings { PreserveObjectReferences = true };
// 序列化对象
string json = JsonConvert.SerializeObject(person, settings);
Console.WriteLine("Serialized JSON:");
Console.WriteLine(json);
// 反序列化对象
Person deserializedPerson = JsonConvert.DeserializeObject(json, settings);
Console.WriteLine("\nDeserialized object:");
Console.WriteLine($"Id: {deserializedPerson.Id}, Name: {deserializedPerson.Name}, Address Id: {deserializedPerson.Address?.Id}");
}
}
输出结果：
Serialized JSON:
{"Id":1,"Name":"John","Address":{"Id":2,"Street":"123 Main St","Person":{"Id":1,"Name":"John","Address":{"Id":2,"Street":"123 Main St","Person":{"Id":1,"Name":"John","Address":{"Id":2,"Street":"123 Main St","Person":{"Id":1,"Name":"John","Address":{"Id":2,"Street":"123 Main St","Person":{"Id":1,"Name":"John","Address":{"Id":2,"Street":"123 Main St","Person":{"Id":1,"Name":"John","Address":{"Id":2,"Street":"123 Main St"}}}}}}}}}}}}
Deserialized object:
Id: 1, Name: John, Address Id: 2
从输出结果可以看出，Newtonsoft.Json成功地处理了循环引用，序列化和反序列化后的对象保持了正确的引用关系。