System.InvalidOperationException: не удалось создать метод получения для System.Threading.ExecutionContext& Context ⇐ C#

[Anonymous]

У меня есть таблицы Stocks и AppUsers, а также таблица Portfolios, которая представляет собой отношения «многие ко многим» между ними. Я хочу получить данные портфелей, но столкнулся с проблемой в моем API. Там написано:

Код: Выделить всё

Newtonsoft.Json.JsonSerializationException: Error getting value from 'Context' on 'System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1+AsyncStateMachineBox`1[System.Collections.Generic.List`1[api.Models.Stock],API.Repositories.Concrete.PortfolioRepository+d__2]'.
---> System.InvalidOperationException: Could not create getter for System.Threading.ExecutionContext& Context.  ByRef return values are not supported.
at Newtonsoft.Json.Utilities.ReflectionDelegateFactory.CreateGet[T](MemberInfo memberInfo)
at Newtonsoft.Json.Serialization.ExpressionValueProvider.GetValue(Object target)
--- End of inner exception stack trace ---
at Newtonsoft.Json.Serialization.ExpressionValueProvider.GetValue(Object target)
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.CalculatePropertyValues(JsonWriter writer, Object value, JsonContainerContract contract, JsonProperty member, JsonProperty property, JsonContract& memberContract, Object& memberValue)
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.Serialize(JsonWriter jsonWriter, Object value, Type objectType)
at Newtonsoft.Json.JsonSerializer.SerializeInternal(JsonWriter jsonWriter, Object value, Type objectType)
at Newtonsoft.Json.JsonSerializer.Serialize(JsonWriter jsonWriter, Object value)
at Microsoft.AspNetCore.Mvc.Formatters.NewtonsoftJsonOutputFormatter.WriteResponseBodyAsync(OutputFormatterWriteContext context, Encoding selectedEncoding)
at Microsoft.AspNetCore.Mvc.Formatters.NewtonsoftJsonOutputFormatter.WriteResponseBodyAsync(OutputFormatterWriteContext context, Encoding selectedEncoding)
at Microsoft.AspNetCore.Mvc.Formatters.NewtonsoftJsonOutputFormatter.WriteResponseBodyAsync(OutputFormatterWriteContext context, Encoding selectedEncoding)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g__Awaited|30_0[TFilter,TFilterAsync](ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResultExecutedContextSealed context)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.ResultNext[TFilter,TFilterAsync](State& next, Scope& scope, Object& state, Boolean& isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeResultFilters()
--- End of stack trace from previous location ---
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g__Awaited|20_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)
at Swashbuckle.AspNetCore.SwaggerUI.SwaggerUIMiddleware.Invoke(HttpContext httpContext)
at Swashbuckle.AspNetCore.Swagger.SwaggerMiddleware.Invoke(HttpContext httpContext, ISwaggerProvider swaggerProvider)
at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddlewareImpl.Invoke(HttpContext context)

Мой контроллер:

Код: Выделить всё

[HttpGet]
[Authorize]
public async Task GetUserPortfolio()
{
var username = User.GetUsername();
var appUser = await userManager.FindByNameAsync(username);
var userPortfolio = portfolioReposiotry.GetUserPortfolio(appUser);
return Ok(userPortfolio);
}

Мой репозиторий:

Код: Выделить всё

public class PortfolioRepository : IPortfolioRepository
{
private readonly AppDbContext context;

public PortfolioRepository(AppDbContext context)
{
this.context = context;
}

public async Task GetUserPortfolio(AppUser user)
{
var val = context.Portfolios.Where(u => u.AppUserId == user.Id)
.Select(stock =>  new Stock
{
Id = stock.StockId,
Symbol = stock.Stock.Symbol,
CompanyName = stock.Stock.CompanyName,
Purchase = stock.Stock.Purchase,
LastDiv = stock.Stock.LastDiv,
Industry = stock.Stock.Industry,
MarketCap = stock.Stock.MarketCap
});
return await val.ToListAsync();
}
}

Не знаю, нужно ли что-то еще. Если да, дайте мне знать.
Я не пробовал никаких решений, так как понятия не имею, что происходит.

Подробнее здесь: https://stackoverflow.com/questions/783 ... hreading-e