在不使用唯一属性名的情况下反序列化JSON [英] Deserializing JSON Without Unique Property Name

问题描述

我有一个类似于以下内容的json字符串

I have a json string that looks like the following

{
    "1ST": {
        "name": "One",
        "symbol": "1st"
    },
    "2ND": {
        "name": "Two",
        "symbol": "2nd"
    }
}

我正在尝试将其序列化为C#对象.看起来它正在创建字典，因此我创建了以下结构

Im trying to Serialize it down to a C# object. It looks like it is creating a Dictionary, so i have created the following structure

public class Response
{
    public Dictionary<string, Item> Objects { get; set; }
}

public class Item
{
    public string name { get; set; }
    public string symbol { get; set; }
}

在序列化过程中，运行以下

And during serialization running the following

response = JsonConvert.DeserializeObject<Response>(jsonString);

它不会在反序列化上引发错误，但是我的回答只是返回为null.我想念什么?

It doesnt throw an error on Deserialization, but my response just comes back as null. What am i missing?

推荐答案

您已经有了正确的基本概念，但是您却没有真正想要的额外的Objects属性:JSON 是有效的字典.您可以将其直接反序列化为Dictionary<string, Item>>.这是一个示例:

You've got the right basic idea, but you've got an extra Objects property that you don't really want: your JSON is the dictionary, effectively. You can deserialize it directly to a Dictionary<string, Item>>. Here's an example:

using System;
using System.Collections.Generic;
using System.IO;
using Newtonsoft.Json;

public class Item
{
    public string Name { get; set; }
    public string Symbol { get; set; }

    public override string ToString() => $"{Name}/{Symbol}";
}

public class Test
{
    static void Main()
    {
        var json = File.ReadAllText("test.json");
        var dictionary = JsonConvert.DeserializeObject<Dictionary<string, Item>>(json);
        foreach (var entry in dictionary)
        {
            Console.WriteLine($"{entry.Key}: {entry.Value}");
        }
    }
}

输出:

1ST: One/1st
2ND: Two/2nd

现在，如果您需要您的Response类型，则有多种选择:

Now if you need your Response type, there are various options:

• 使从Dictionary<string, Item>派生的内容并删除Objects属性. (如果需要Objects属性，效果不好.)
• 反序列化到字典，然后创建一个新的Response对象并自行分配属性. (如果响应是其他类型的一部分，则不好.)
• 调查Json.NET是否具有某些属性，以将Objects视为一种根"属性.

• Make that derive from Dictionary<string, Item> and remove the Objects property. (Not good if you need the Objects property.)
• Deserialize to the dictionary, but then create a new Response object and assign the property yourself. (Not good if the response is part of another type.)
• Investigate whether there's some attribute for Json.NET to treat Objects as a sort of "root" property.

在最后一个方面，我有些运气，但还不是一个完整的解决方案.如果将Objects更改为Dictionary<string, JToken>，则可以将[JsonExtensionData]应用于它，这使其成为任何不匹配属性的默认词典.但是，我还没有找到说服Json.NET使用该属性 并执行适当转换的方法.您可以创建一个字典，该字典在每次添加条目时都执行从JToken到Item的转换(使用常规的Json.NET代码)，然后将该值添加到另一个字典中-但这很丑陋.这可能只是Json.NET无法处理的情况.

I've had some luck with the last aspect, but not a complete solution. If you change Objects to a Dictionary<string, JToken> then you can apply the [JsonExtensionData] to it, which makes it act as a default dictionary for any unmatched property. However, I haven't found a way of persuading Json.NET to use that attribute and perform the appropriate conversion. You could create a dictionary which performed the conversion from JToken to Item (using regular Json.NET code) every time an entry was added to it, and then added that value to another dictionary - but that's pretty ugly. This may just be a case that Json.NET doesn't handle.

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