Cannot deserialize the current JSON array during API call

Question

I was learning how to consume API's and got stuck with the error "Cannot deserialize the current JSON array (e.g. [1,2,3]) into type 'NbaApi.Models.Standard' because the type requires a JSON object (e.g. {"name":"value"}) to deserialize correctly." Thank you in advance!

I have this json

{
  "_internal": {
    "pubDateTime": "2020-04-03 13:11:16.692 EDT",
    "igorPath": "S3,1585933850069,1585933857347|router,1585933857347,1585933857352|domUpdater,1585933857484,1585933875507|feedProducer,1585933875618,1585933885453",
    "xslt": "NBA/xsl/league/roster/marty_active_players.xsl",
    "xsltForceRecompile": "true",
    "xsltInCache": "false",
    "xsltCompileTimeMillis": "253",
    "xsltTransformTimeMillis": "7800",
    "consolidatedDomKey": "prod__transform__marty_active_players__1989425396229",
    "endToEndTimeMillis": "35384"
  },
  "league": {
    "standard": [
      {
        "firstName": "Steven",
        "lastName": "Adams",
        "temporaryDisplayName": "Adams, Steven",
        "personId": "203500",
        "teamId": "1610612760",
        "jersey": "12",
        "isActive": true,
        "pos": "C",
        "heightFeet": "6",
        "heightInches": "11",
        "heightMeters": "2.11",
        "weightPounds": "265",
        "weightKilograms": "120.2",
        "dateOfBirthUTC": "1993-07-20",
        "teamSitesOnly": {
          "playerCode": "steven_adams",
          "posFull": "Center",
          "displayAffiliation": "Pittsburgh/New Zealand",
          "freeAgentCode": ""
        },
        "teams": [
          {
            "teamId": "1610612760",
            "seasonStart": "2013",
            "seasonEnd": "2019"
          }
        ],
        "draft": {
          "teamId": "1610612760",
          "pickNum": "12",
          "roundNum": "1",
          "seasonYear": "2013"
        },
        "nbaDebutYear": "2013",
        "yearsPro": "6",
        "collegeName": "Pittsburgh",
        "lastAffiliation": "Pittsburgh/New Zealand",
        "country": "New Zealand"
      }
    ]
  }
}

I have these model classes

public class Data
    {
        public League League { get; set; }
    }

    public class League
    {
        public Standard Standard { get; set; }
    }
    public class Standard
    {
        public List<Player> players { get; set; }
    }
    public class Player
    {
        public string FirstName { get; set; }
        public string LastName { get; set; }
        //other parameters are also in the model
    }

And I use this method to consume the api and pass it to the model

   class Program
    {
        static void Main(string[] args)
        {
            var data = new List<Data>();
            Player player = new Player();

            using (var client = new HttpClient())
            {


                client.BaseAddress = new Uri("http://data.nba.net/10s/prod/v1/2019/players.json");
                //HTTP GET
                var responseTask = client.GetAsync("");
                responseTask.Wait();

                var result = responseTask.Result;
                if (result.IsSuccessStatusCode)
                {
                    var readTask = result.Content.ReadAsAsync<List<Data>>();
                    readTask.Wait();

                    data = readTask.Result;
                    foreach (var item in data)
                    {
                        var league = item.League;
                        var standard = league.Standard;
                        var players = standard.players;
                        player = players.Where(p => p.LastName == "Adams").First();
                    }

                }
                else
                {
                    throw new Exception(result.ReasonPhrase);
                }
            }
            Console.WriteLine(player.LastName);

            Console.ReadLine();
        }
    }

Answer 1

You need change your model as below

public class TeamSitesOnly
{
    public string playerCode { get; set; }
    public string posFull { get; set; }
    public string displayAffiliation { get; set; }
    public string freeAgentCode { get; set; }
}

public class Team
{
    public string teamId { get; set; }
    public string seasonStart { get; set; }
    public string seasonEnd { get; set; }
}

public class Draft
{
    public string teamId { get; set; }
    public string pickNum { get; set; }
    public string roundNum { get; set; }
    public string seasonYear { get; set; }
}

public class Standard
{
    public string firstName { get; set; }
    public string lastName { get; set; }
    public string temporaryDisplayName { get; set; }
    public string personId { get; set; }
    public string teamId { get; set; }
    public string jersey { get; set; }
    public bool isActive { get; set; }
    public string pos { get; set; }
    public string heightFeet { get; set; }
    public string heightInches { get; set; }
    public string heightMeters { get; set; }
    public string weightPounds { get; set; }
    public string weightKilograms { get; set; }
    public string dateOfBirthUTC { get; set; }
    public TeamSitesOnly teamSitesOnly { get; set; }
    public List<Team> teams { get; set; }
    public Draft draft { get; set; }
    public string nbaDebutYear { get; set; }
    public string yearsPro { get; set; }
    public string collegeName { get; set; }
    public string lastAffiliation { get; set; }
    public string country { get; set; }
}

public class League
{
    public List<Standard> standard { get; set; }
}

public class Data
{
    public League league { get; set; }
}

You can use online tool to convert JSON object to C# class structure by http://json2csharp.com/

Answer 2

Change your model (since standard is an array, not an object):

    public class League
    {
        public List<Player> Standard { get; set; }
    }

The response object has structure:

{
  "league": {
    "standard": [...]
  }
}

While your current model tries to deserialize:

{
  "league": {
    "standard": {
      "players": [...]
    }
  }
}