C＃：返回通用列表的问题

Question

I have this code:

Model:

using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace MyAplication.Models
{
  public class Result
  {
    public string MarketName { get; set; }
    public double High { get; set; }
    public double Low { get; set; }
    public double Volume { get; set; }
    public double Last { get; set; }
    public double BaseVolume { get; set; }
    public DateTime TimeStamp { get; set; }
    public double Bid { get; set; }
    public double Ask { get; set; }
    public int OpenBuyOrders { get; set; }
    public int OpenSellOrders { get; set; }
    public double PrevDay { get; set; }
    public DateTime Created { get; set; }
  }

  public class RootInfoCoins
  {
      public bool success { get; set; }
      public string message { get; set; }        
      public List<Result> result { get; set; }        
  }
}

And this class:

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Threading.Tasks;
    using Microsoft.AspNetCore.Http;
    using Microsoft.AspNetCore.Mvc;
    using PeekAndGoApp.Models;
    using System.Net.Http;
    using System.Net.Http.Headers;
    using Newtonsoft.Json;
    using System.Collections;

    namespace MyAplication.Controllers
    {
        [Produces("application/json")]
        [Route("api/[controller]")]
        [ApiController]
        public class CoinsController : ControllerBase
        {
            [HttpGet]
            public async Task<IEnumerable<RootInfoCoins>> Get()
            {
                string Baseurl = "https://bittrex.com";
                string Parameters = "api/v1.1/public/getmarketsummaries";
                RootInfoCoins CoinsInfo = new RootInfoCoins();                  

                using (var client = new HttpClient())
                {
                    //Passing service base url  
                    client.BaseAddress = new Uri(Baseurl);

                    client.DefaultRequestHeaders.Clear();
                    //Define request data format  
                    client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

                    //Sending request to find web api REST service resource GetAllCoins using HttpClient  
                    HttpResponseMessage Res = await client.GetAsync(Parameters);

                    //Checking the response is successful or not which is sent using HttpClient  
                    if (Res.IsSuccessStatusCode)
                    {
                        //Storing the response details recieved from web api   
                        string CoinResponse = Res.Content.ReadAsStringAsync().Result;                                               
                        CoinsInfo = JsonConvert.DeserializeObject<RootInfoCoins>(CoinResponse);
                    }
                    return CoinsInfo.result;                        
                }
            }
        }
    }

My problem is that i try to return my data and get this:

"Cannot implicitly convert type 'System.Collections.Generic.List' to 'System.Collections.Generic.IEnumerable'. An explicit conversion exists (are you missing a cast?)"

I'm new in C# (i'm learning). I've done a lot of research and i can't resolve my problem. Maybe I'm not understanding the concepts of this language. Please, can someone help me?

PS: I have attached an image so that you can see "the format" of the data I am receiving.

Thanks a lot.

Jhon.

Answer 1

Get() expects to return IEnumerable<RootInfoCoins> , but you are trying to return List<Result> . You can either return the RootInfoCoins created from JsonConvert by changing the signature and return statement to

public async Task<RootInfoCoins> Get()
{
    //...
    return coinsInfo;
}

Or return List<Result> by changing the signature to

public async Task<IEnumerable<Result>> Get() { }

Answer 2

    [HttpGet]
    public async Task<IEnumerable<Result>> Get()
    {
        string Baseurl = "https://bittrex.com";
        string Parameters = "api/v1.1/public/getmarketsummaries";
        RootInfoCoins CoinsInfo = new RootInfoCoins();

        using (var client = new HttpClient())
        {
            //Passing service base url  
            client.BaseAddress = new Uri("");

            client.DefaultRequestHeaders.Clear();
            //Define request data format  
            client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

            //Sending request to find web api REST service resource GetAllCoins using HttpClient  
            HttpResponseMessage Res = await client.GetAsync(Parameters);

            //Checking the response is successful or not which is sent using HttpClient  
            if (Res.IsSuccessStatusCode)
            {
                //Storing the response details recieved from web api   
                string CoinResponse = Res.Content.ReadAsStringAsync().Result;
                CoinsInfo = JsonConvert.DeserializeObject<RootInfoCoins>(CoinResponse);
            }

            return CoinsInfo.result;

        }

change this because CoinsInfo.result is a List type so, you change the return type

  public async Task<IEnumerable<Result>> Get()