C# WinForms - How to parse json correctly?

Question

JSON

I am writing a program with VK Api, I made a GET request, then I had problems with json parsing. When I run the program, nothing is displayed... Here is the code:

public class Account
        {
            public string id { get; set; }
            public string first_name { get; set; }
            public string last_name { get; set; }
            public string bdate { get; set; }
        }

    private void Example_Load(object sender, EventArgs e)
        {
            var client = new WebClient();
            using (var stream = client.OpenRead("https://api.vk.com/method/users.get?user_ids=210700286&fields=bdate&v=5.64"))
            using (var sr = new StreamReader(stream))
            {
                var text = sr.ReadToEnd();

                Account m = JsonConvert.DeserializeObject<Account>(text);
                
                textBox1.Text = m.id;
                textBox1.Text += " ";
                textBox1.Text += m.first_name;
                textBox1.Text += " ";
                textBox1.Text += m.last_name;
                textBox1.Text += " ";
                textBox1.Text += m.bdate;
            }
        }

What is the problem? Thank you very much in advance

Answer 1

1. Why use stream when you can use client.DownloadString?
2. The response comes with an array of accounts. That is, you need something like this:

public class Response 
        {
            public List<Account> response { get; set; }
        }
public class Account
        {
            public int id { get; set; }
            public string first_name { get; set; }
            public string last_name { get; set; }
            public string bdate { get; set; }
        }

... 
Response m = JsonConvert.DeserializeObject<Response>(text);

Written out of my head, but the idea is clear, I hope.

Answer 2

How to parse, I think you will understand from my shit code :)

using System;
using System.Data;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;
using Newtonsoft.Json.Linq;
using System.Diagnostics;
using System.Collections.Generic;
using Newtonsoft.Json;

{List<string>Admins = new List<string>();
                        try
                        {
                            JToken fdbdb = JObject.Parse(await Download("https://api.vk.com/method/groups.getById?v=5.64&fields=contacts,deactivated,members_count&group_id=" + GROUPS[K]))["response"];
                            if (fdbdb[0]["deactivated"] != null)//группа забанена (временно или нет)
                            {
                                fuckthewall = true; fuckthetopics = true; isNeedToCheck = false;
                            }
                            if (Convert.ToUInt32(fdbdb[0]["members_count"]) < MinimalMembeers)//мало подписчиков
                            {
                                fuckthewall = true; fuckthetopics = true; isNeedToCheck = false;
                            }
                            JToken GroupContacts = fdbdb[0]["contacts"];
                            if (GroupContacts == null) GroupContacts = 0;
                            for (int j = 0; j < GroupContacts.Count(); j++)
                            {
                                JToken gjdfj = GroupContacts[j]["user_id"];
                                if (gjdfj != null) Admins.Add(gjdfj.ToString());
                            }
                        }
                        catch{}
}
{
json = JObject.Parse(await Download("https://api.vk.com/method/wall.get?v=5.64&count=30&owner_id=-" + GROUPS[K]));
                                if (!json.ToString().Contains("error"))
                                {
                                    posts = (JArray)json["response"]["items"];
                                    var query = from post in posts
                                                select new
                                                {
                                                    id = post["id"],
                                                    date = post["date"],
                                                    from_id = post["from_id"],//идентификатор автора записи. 
                                                    text = post["text"],
                                                    owner_id = post["owner_id"]//идентификатор владельца стены, на которой размещена запись. 
                                                };
                                    int posttobreak = 2;
                                    foreach (var post in query)
                                    {
                                        DateTime Postdate = UnixTimeToDate(Convert.ToDouble(post.date));
                                        if ((DateTimeNow - Postdate).Days < 10 || posttobreak > 0)//проверяем посты не старше 30 дней, но также проверяем парочку
                                        {//первых записей, т.к. закрепленная запись выводится первой и у ней могут быть актуальные комменты, и может быть старше 30 дней, а вторая (по факту самая новая), может быть младше 30 дней
                                            if ((DateTimeNow - Postdate) < c)//если пост опубликован после предыдущей проверки
                                                if (!IsAdmin(Admins, post.from_id.ToString()))//если пост написан не админом                                                
                                                    if (Convert.ToInt32(post.from_id) > 0)//проверяем пост на стене
                                                        if (post.text.ToString().Length > CommentLen)//если пост содержит текст  
//
....
}}}

}

download function

private async Task<string> Download(string whattodownload)
        {
            string returnstring = "";
            using (WebClient w = new WebClient())
            {
                w.Encoding = Encoding.UTF8;
                int ErrorsCount = 0;
                bool downloaded = false;
                while (downloaded == false)//периодически пытаемся скачать строку
                {
                    try
                    {
                        returnstring = await w.DownloadStringTaskAsync(whattodownload);
                        downloaded = true;
                    }
                    catch
                    {
                        downloadingErrors++;
                        downloaded = false; ErrorsCount++; toomanyrequests += 2; Thread.Sleep(2000);
                        if (ErrorsCount > 10)
                        {
                            ErrorsCount = 0;
                            try
                            {
                                using (WebClient w2 = new WebClient())
                                {
                                    returnstring = await w2.DownloadStringTaskAsync(whattodownload);
                                    downloaded = true; break;
                                }
                            }
                            catch { }
                        }
                    }
                }
            }
            try
            {
                if (returnstring.Contains("Too many requests per second"))//Если в скачанной строке есть ошибка
                {
                    while (returnstring.Contains("Too many requests per second"))//то в цикле пытаемся снова скачать данные пока не скачаем
                    {
                        Thread.Sleep(2500); toomanyrequests += 2.5;
                        using (WebClient w2 = new WebClient())
                        {
                            w2.Encoding = Encoding.UTF8;
                            returnstring = await w2.DownloadStringTaskAsync(whattodownload);
                        }
                    }
                }
            }
            catch
            {
                downloadingErrors++;
                using (WebClient w2 = new WebClient())
                {
                    Thread.Sleep(2500); toomanyrequests += 2.5;
                    w2.Encoding = Encoding.UTF8;
                    returnstring = await w2.DownloadStringTaskAsync(whattodownload);
                }
            }
            return returnstring;//Если в скачанной строке не было ошибки "Too many requests per second" - все ОК, значит возвращаем ответ сервера
        }

Answer 3

https://www.youtube.com/watch?v=NiZY7EmFSCE