无效的ModelState，发送给C＃Web API控制器的JSON数组的HTTP 400错误请求

Question

In a C# Web API, I am trying to accept a POST request that contains a JSON array. I want to deserialize the JSON array to a LIST or ILIST of RegisterBindingModel class objects. Then, in the controller actions, I will iterate over the list and perform the desired action.

I am using essentially the stock ASP.NET 5 Web Application template in Visual Studio 2015. I have added a RegisterList method on the Account controller.

Separately, I have created a Web client in a C# console application. The client sends a POST request that contains a JSON array.

The response I get is always 400 - Bad Request.

Am I supposed to deserialize the JSON array to an ILIST or LIST in the RegisterList method signature? I've tried to use JsonConverter.DeserializeObject , but IntelliSenese says that the type name DeserializeObject does not exist in type JsonConverter .

The API documentation that generates with the Visual Studio template indicates that the client's JSON array is formatted correctly.

The following is the code for the RegisterList method:

        // POST api/Account/RegisterList
    [AllowAnonymous]
    [Route("RegisterList")]
    public async Task<IHttpActionResult> RegisterList(List<RegisterBindingModel> modelList)
    {
        if (!ModelState.IsValid)
        {
            return BadRequest(ModelState);
        }

        foreach (RegisterBindingModel model in modelList)
        {
            var user = new ApplicationUser() { UserName = model.Email, Email = model.Email };

            IdentityResult result = await UserManager.CreateAsync(user, model.Password);

            if (!result.Succeeded)
            {
                return GetErrorResult(result);
            }

        }
        return Ok();
    }

The following is the code for the client:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Net.Http;
using System.Net.Http.Headers;
using Web_Client_Register_Account;
using Newtonsoft.Json;

namespace Web_Client_Register_Account
{
class Program
{
    static void Main(string[] args)
    {
        RunAsync().Wait();
    }

    static async Task RunAsync()
    {
        using (var client = new HttpClient())
        {
            Console.WriteLine("Hit any key");
            Console.ReadLine();
            client.BaseAddress = new Uri("http://localhost:9000/");
            client.DefaultRequestHeaders.Accept.Clear();
            client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));





            var registrations = new List<Registration> { new Registration { Email = "orc@coast2coast.net", Password = "Secrets1!", ConfirmPassword = "Secrets1!" }, new Registration { Email = "gargoyle@coast2coast.net", Password = "Secrets1!", ConfirmPassword = "Secrets1!" }, new Registration { Email = "elf@coast2coast.net", Password = "Secrets1!", ConfirmPassword = "Secrets1!" }, new Registration { Email = "ranger@coast2coast.net", Password = "Secrets1!", ConfirmPassword = "Secrets1!" } };

    //HTTP Post - A JSON List in a Single POST

            var registration_manifest = JsonConvert.SerializeObject(registrations);

            Console.ReadLine();

                HttpResponseMessage response = await client.PostAsJsonAsync("api/Account/RegisterList", registration_manifest);


                if (response.IsSuccessStatusCode)
                {
                    Uri registrantUrl = response.Headers.Location;
                    Console.WriteLine(registrantUrl);
                    Console.ReadLine();
                }
                Console.WriteLine(response);
                Console.ReadLine();
        }
    }
}
}

Answer 1

HttpClient.PostAsJsonAsync already encodes to JSON, so skip the JsonConvert.SerializeObject and just

HttpResponseMessage response = await client.PostAsJsonAsync("api/Account/RegisterList", 
                                                            registrations);