使用JsonConverter在C#中自定义JSON反序列化 [英] Custom JSON Deserialization in C# with JsonConverter

问题描述

.Net Core中有两个类

I have two classes in .Net Core

类所有权

namespace CustomStoreDatabase.Models
{
    public class Ownership
    {
        public string OwnershipId { get; set; }
        public List<string> TextOutput { get; set; }
        public DateTime DateTime { get; set; }
        public TimeSpan MeanInterval { get; set; }// Like long ticks, TimeSpan.FromTicks(Int64), TimeSpan.Ticks
    }
}

我需要使用方法 TimeSpan.FromTicks(Int64)和 TimeSpan.Ticks 像长刻度一样显示 MeanInterval .

I need to show MeanInterval like long ticks, using the methods TimeSpan.FromTicks(Int64) and TimeSpan.Ticks.

我的自定义JsonConverter

My custom JsonConverter

using CustomStoreDatabase.Models;
using System;
using System.Text.Json;
using System.Text.Json.Serialization;

namespace CustomStoreDatabase.Util
{
    public class OwnershipJSonConverter : JsonConverter<Ownership>
    {
        public override bool CanConvert(Type typeToConvert)
        {
            return true;
        }

        public override Ownership Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
        {
            if (reader.TokenType != JsonTokenType.StartObject)
            {
                throw new JsonException();
            }
            //*******************
            // HOW TO IMPLEMENT?
            //*******************
            //throw new NotImplementedException();
        }

        public override void Write(Utf8JsonWriter writer, Ownership value, JsonSerializerOptions options)
        {
            writer.WriteStartObject();
            if (value != null)
            {
                writer.WriteString("OwnershipId", value.OwnershipId);
                writer.WriteString("TextOutput", JsonSerializer.Serialize(value.TextOutput));
                writer.WriteString("DateTime", JsonSerializer.Serialize(value.DateTime));
                if (value.MeanInterval != null)
                {
                    writer.WriteNumber("MeanInterval", (long)value.MeanInterval.Ticks);
                }
                else
                {
                    writer.WriteNull("MeanInterval");
                }
            }
            writer.WriteEndObject();
        }
    }
}

我不知道如何实现 Read 方法.如何实现覆盖Read方法的自定义反序列化?

I don't know how to implement the Read method. How can I implement the custom Deserialization overriding the Read method?

如果可能的话，我向我提议了 CanConvert 方法的另一种实现，非常感谢.

If is possible you guys proposal to me another implementation for CanConvert method, I thank you very much.

推荐答案

似乎您只想对 TimeSpan 进行自定义序列化，因为它属于 Ownership ，因此为什么不只为 TimeSpan 创建转换器，并避免手动序列化所有其他类属性呢?

It seems like you only want to perform custom serialization of TimeSpan as it belongs to Ownership, so why not make a converter for TimeSpan only and save yourself from manually serializing all of the other class properties?:

public class TimeSpanConverter : JsonConverter<TimeSpan>
{
    public override TimeSpan Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
    {
        return TimeSpan.FromTicks(reader.GetInt64());
    }

    public override void Write(Utf8JsonWriter writer, TimeSpan value, JsonSerializerOptions options)
    {
        writer.WriteNumberValue(value.Ticks);
    }
}

然后用 JsonConverterAttribute 装饰您的 MeanInterval 属性:

public class Ownership
{
    public string OwnershipId { get; set; }
    public List<string> TextOutput { get; set; }
    public DateTime DateTime { get; set; }
    [JsonConverter(typeof(TimeSpanConverter))]
    public TimeSpan MeanInterval { get; set; }// Like long ticks, TimeSpan.FromTicks(Int64), TimeSpan.Ticks
}

在线试用

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