以数字为键反序列化 JSON [英] Deserializing JSON with numbers as keys

问题描述

我想出了如何获取每个键，现在问题是循环遍历每个集合.底部的解决方案！

我正在尝试解析具有以下格式的 JSON 有效负载:

I'm trying to parse a JSON payload that has the following format:

{
    "version": "1.1", 
    "0": {
              "artist": "Artist 1",
              "title": "Title 1"
         },
    "1": {
              "artist": "Artist 2",
              "title": "Title 2"
         },
    ...
    "29": {
              "artist": "Artist 30",
              "title": "Title 30"
         }
}

我不需要 version 键，所以我在编写课程时忽略了它.这是我目前所拥有的:

I don't need the version key, so I'm ignoring it while coding my classes. This is what I have so far:

public class Song
{
    public string artist { get; set; }
    public string title { get; set; }
}

我检查了 StackOverflow，看到有人使用 Dictionary<int, string> 解决类似问题，但看起来人们在根目录中没有每个 JSON 对象.我正在使用 JSON.net 来解析所有内容.

I've checked around StackOverflow and I've seen people using Dictionary<int, string> for similar problems, but it doesn't look like people have each JSON object in the root. I'm using JSON.net to parse everything.

在 PHP 中，我可以轻松地使用 json_decode() 并遍历数组并提取我需要的所有信息，但我被 C# 难住了.

In PHP, I could easily use json_decode() and walk through the array and extract all the info I need, but I'm stumped by C#.

解决方案从下面开始.

我查看了 JSON.net 文档，他们使用字典，所以我尝试使用嵌套字典，它似乎工作！

I looked at the JSON.net documentation and they used dictionaries, so I tried using nested dictionaries, and it seems to work!

Dictionary<int, Dictionary<string, string>> song = JsonConvert.DeserializeObject<Dictionary<int, Dictionary<string, string>>>(json);

我可以通过以下方式访问 artist 和 title 属性:

And I can access the artist and title properties via:

song[0]["artist"]
song[0]["title"]

分别.

这消除了对预构建类的需要.现在，我无法循环遍历每组数据集合(例如歌曲 [1]、歌曲 [2]、歌曲 [3]、...、歌曲 [n] 的艺术家和标题信息).

This eliminates the need for pre-built classes. Now I'm having trouble looping through each set of data collection (e.g. artist and title info for song[1], song[2], song[3], ..., song[n]).

推荐答案

如果你尝试用上面的 JSON 反序列化成 Dictionary 你是version 键会遇到问题，因为它不适合字典的数据格式(version 不是 int，并且 1.1 不是 Dictionary).我知道你说你暂时忽略它"，但这意味着它将来会在那里，所以你需要处理它.

If you try to deserialize into a Dictionary<int, Dictionary<string, string>> with the above JSON you're going to run into problems with the version key because it does not fit the data format for the dictionaries (version is not an int, and 1.1 is not a Dictionary<string, string>). I know you said you're "ignoring it for now", but that implies that it will be there in the future, so you need to handle it.

如果你不想有预定义的类，那么你最好使用 Json.Net 的 LINQ-to-JSON API 来处理数据.以下是使用这种方法获取所需数据的方法:

If you don't want to have pre-defined classes, then you're better off using Json.Net's LINQ-to-JSON API to work with the data. Here is how you can get the data you want using this approach:

class Program
{
    static void Main(string[] args)
    {
        string json = @"
        {
            ""version"": ""1.1"", 
            ""0"": {
                      ""artist"": ""Artist 1"",
                      ""title"": ""Title 1""
                 },
            ""1"": {
                      ""artist"": ""Artist 2"",
                      ""title"": ""Title 2""
                 },
            ""29"": {
                      ""artist"": ""Artist 30"",
                      ""title"": ""Title 30""
                 }
        }";

        JObject songs = JObject.Parse(json);

        foreach (JProperty song in songs.Properties())
        {
            if (song.Name == "version") continue;  // skip "version" property
            Console.WriteLine("Song " + song.Name + " artist: " + song.Value["artist"]);
            Console.WriteLine("Song " + song.Name + " title: " + song.Value["title"]);
        }
    }
}

输出:

Song 0 artist: Artist 1
Song 0 title: Title 1
Song 1 artist: Artist 2
Song 1 title: Title 2
Song 29 artist: Artist 30
Song 29 title: Title 30

文档.

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