C# JSON 对象不会反序列化

Question

所以我已经能够为一些事情获取 JSON 对象，但是这个对象要复杂得多。

我正在尝试从 Reddit 获取 cmets。 这是我使用的方法：

    public async Task<List<string>> GetComments(string currentSubreddit, string topicID)
    {
        string commentUrl = "http://www.reddit.com/r/" + currentSubreddit  + "/comments/" + topicID + "/.json";
        List<Comments> commentList = new List<Comments>();
        string jsonText = await wc.GetJsonText(commentUrl);

        Comments.RootObject deserializeObject = Newtonsoft.Json.JsonConvert.DeserializeObject<Comments.RootObject>(jsonText);

        List<string> commentListTest = new List<string>();
        //List<string> commentListTest = deserializeObject.data.children[0].data.children;
        return commentListTest;

    }

这是 GetJsonText 方法：

    public async Task<string> GetJsonText(string url)
    {
        var request = WebRequest.Create(url);
        string text;
        request.ContentType = "application/json; charset=utf-8";
        var response = (HttpWebResponse)await request.GetResponseAsync();

        using (var sr = new StreamReader(response.GetResponseStream()))
        {
            text = sr.ReadToEnd();
        }

        return text;
    }

这里是对象的链接：http://pastebin.com/WQ8XXGNA 以及指向 jsonText 的链接：http://pastebin.com/7Kh6cA9a

返回的错误是这样的：

“Newtonsoft.Json.JsonSerializationException”类型的异常发生在 mscorlib.dll 中，但未在用户代码中处理

附加信息：无法将当前 JSON 数组（例如 [1,2,3]）反序列化为类型 'JuicyReddit.Comments+RootObject'，因为该类型需要 JSON 对象（例如 {"name":"value"}）正确反序列化。

如果有人能帮助我找出问题所在，我将不胜感激。 谢谢

Answer 1

实际上你的代码有一些问题

 public async Task<List<string>> GetComments(string currentSubreddit, string topicID)

这里你不需要返回一个字符串列表，你需要返回一个完整的对象

首先将模型中的 RootObject 重命名为适当的名称，例如“CommentsObject”

所以像这样设置你的类并将其命名为 CommentsObject.cs：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace YOURNAMESPACE.Comments
{
    public class MediaEmbed
    {
    }

    public class SecureMediaEmbed
    {
    }

    public class Data4
    {
        public int count { get; set; }
        public string parent_id { get; set; }
        public List<string> children { get; set; }
        public string name { get; set; }
        public string id { get; set; }
        public string subreddit_id { get; set; }
        public object banned_by { get; set; }
        public string subreddit { get; set; }
        public object likes { get; set; }
        public object replies { get; set; }
        public bool? saved { get; set; }
        public int? gilded { get; set; }
        public string author { get; set; }
        public object approved_by { get; set; }
        public string body { get; set; }
        public object edited { get; set; }
        public object author_flair_css_class { get; set; }
        public int? downs { get; set; }
        public string body_html { get; set; }
        public string link_id { get; set; }
        public bool? score_hidden { get; set; }
        public double? created { get; set; }
        public object author_flair_text { get; set; }
        public double? created_utc { get; set; }
        public object distinguished { get; set; }
        public object num_reports { get; set; }
        public int? ups { get; set; }
    }

    public class Child2
    {
        public string kind { get; set; }
        public Data4 data { get; set; }
    }

    public class Data3
    {
        public string modhash { get; set; }
        public List<Child2> children { get; set; }
        public object after { get; set; }
        public object before { get; set; }
    }

    public class Replies
    {
        public string kind { get; set; }
        public Data3 data { get; set; }
    }

    public class Data2
    {
        public string domain { get; set; }
        public object banned_by { get; set; }
        public MediaEmbed media_embed { get; set; }
        public string subreddit { get; set; }
        public object selftext_html { get; set; }
        public string selftext { get; set; }
        public object likes { get; set; }
        public object secure_media { get; set; }
        public object link_flair_text { get; set; }
        public string id { get; set; }
        public SecureMediaEmbed secure_media_embed { get; set; }
        public bool clicked { get; set; }
        public bool stickied { get; set; }
        public string author { get; set; }
        public object media { get; set; }
        public int score { get; set; }
        public object approved_by { get; set; }
        public bool over_18 { get; set; }
        public bool hidden { get; set; }
        public string thumbnail { get; set; }
        public string subreddit_id { get; set; }
        public object edited { get; set; }
        public object link_flair_css_class { get; set; }
        public object author_flair_css_class { get; set; }
        public int downs { get; set; }
        public bool saved { get; set; }
        public bool is_self { get; set; }
        public string permalink { get; set; }
        public string name { get; set; }
        public double created { get; set; }
        public string url { get; set; }
        public object author_flair_text { get; set; }
        public string title { get; set; }
        public double created_utc { get; set; }
        public int ups { get; set; }
        public int num_comments { get; set; }
        public bool visited { get; set; }
        public object num_reports { get; set; }
        public object distinguished { get; set; }
        public Replies replies { get; set; }
        public int? gilded { get; set; }
        public string parent_id { get; set; }
        public string body { get; set; }
        public string body_html { get; set; }
        public string link_id { get; set; }
        public bool? score_hidden { get; set; }
        public int? count { get; set; }
        public List<string> children { get; set; }
    }

    public class Child
    {
        public string kind { get; set; }
        public Data2 data { get; set; }
    }

    public class Data
    {
        public string modhash { get; set; }
        public List<Child> children { get; set; }
        public object after { get; set; }
        public object before { get; set; }
    }

    public class CommentsObject
    {
        public string kind { get; set; }
        public Data data { get; set; }
    }
}

让你的命名空间正确！

然后处理请求并反序列化为commentobjects列表：（如果你愿意，你可以使用webclient而不是httpclient，这只是一个例子）

    private HttpClient client;

    public async Task<List<CommentsObject>> GetComments()
    {
        client = new HttpClient();
        var response = await client.GetAsync("http://www.reddit.com/r/AskReddit/comments/1ut6xc.json");
        if (response.IsSuccessStatusCode)
        {
            string json = await response.Content.ReadAsStringAsync();
            List<CommentsObject> comments = await JsonConvert.DeserializeObjectAsync<List<CommentsObject>>(json);
            return comments;
        }
        else
        {
            throw new Exception("Errorhandling message");
        }
    }

Answer 2

这并不理想（也不是完全的答案，而是更多的解决方法），但我创建了模拟 reddit 响应 json 的模型，以使反序列化超级容易。我在模型属性上使用 JsonProperty 属性来美化模型。

Here are the models

由于我的模型直接模拟了 json，我可以使用 json.net 的通用反序列化方法。