Json.net反序列化null GUID案例

使用Json.net进行反序列化时，有时会遇到null GUID的情况。在本文中，我们将介绍如何处理这种情况，并提供一个案例代码来说明这个过程。

csharp
using System;
using Newtonsoft.Json;
public class NullGuidConverter : JsonConverter
{
    public override bool CanConvert(Type objectType)
    {
        return objectType == typeof(Guid);
    }
    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        if (reader.Value == null)
        {
            return Guid.Empty;
        }
        
        return new Guid(reader.Value.ToString());
    }
    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        throw new NotImplementedException();
    }
}

csharp
public class Person
{
    [JsonConverter(typeof(NullGuidConverter))]
    public Guid Id { get; set; }
    public string Name { get; set; }
}
public class Program
{
    static void Main(string[] args)
    {
        string json = "{\"Id\":null,\"Name\":\"John\"}";
        Person person = JsonConvert.DeserializeObject(json);
        Console.WriteLine($"Id: {person.Id}");
        Console.WriteLine($"Name: {person.Name}");
    }
}

Id: 00000000-0000-0000-0000-000000000000
Name: John