Error 500 "Queries cannot be applied to the response content of type 'System.Net.Http.ByteArrayContent'

Question

I am trying to Output Cache in my Webapi . I have installed Nuget package "Strathweb.CacheOutput.WebApi2" as per discussion in the article below https://github.com/filipw/Strathweb.CacheOutput. After installation I used:

[CacheOutput(ClientTimeSpan = 100, ServerTimeSpan = 100, AnonymousOnly = true)]
    public HttpResponseMessage Get()
    {
        var list = context.Colors.ToList();
        return Request.CreateResponse(HttpStatusCode.OK,list.AsQueryable<Color>() );
    }

It returns this error:

{"Message":"An error has occurred.","ExceptionMessage":"Queries can not be applied to a response content of type 'System.Net.Http.ByteArrayContent'. The response content must be an ObjectContent.\r\nParameter name: actionExecutedContext","ExceptionType":"System.ArgumentException","StackTrace":" at System.Web.Http.OData.EnableQueryAttribute.OnActionExecuted(HttpActionExecutedContext actionExecutedContext)\r\n at System.Web.Http.Filters.ActionFilterAttribute.OnActionExecutedAsync(HttpActionExecutedContext actionExecutedContext, CancellationToken cancellationToken)\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.Filters.ActionFilterAttribute.d__5.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.Filters.ActionFilterAttribute.d__0.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.Controllers.ActionFilterResult.d__2.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.Controllers.AuthenticationFilterResult.d__0.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.Dispatcher.HttpControllerDispatcher.d__1.MoveNext()"}

What Can I do to resolve this issue. I am new with Web Api . Thanks

Marcus Höglund Marcus Höglund · Accepted Answer · 2016-12-22T08:49:12

As the Web Api is the last step in the server side chain the IQueryable needs to be executed / evaluated before sending it with the response. So the simple solution is just sending the list as it is

public HttpResponseMessage Get()
{
    var list = context.Colors.ToList();
    return Request.CreateResponse(HttpStatusCode.OK,list);
}

Error 500 "Queries cannot be applied to the response content of type 'System.Net.Http.ByteArrayContent'

1 Answers