ModelState.IsValid even when it should not be?

Question

I have API where I need to validate my user model. I choose an approach where I create different classes for Create/Edit actions to avoid mass-assignment and divide validati

Answer 1

Try

services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2);

in the startup.cs file's ConfigureServices()

Answer 2

I wrote a custom filter which not only ensures that all non optional object properties are passed, but also checks if model state is valid:

[AttributeUsage (AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = false)]
public sealed class ValidateModelAttribute : ActionFilterAttribute
{
    private static readonly ConcurrentDictionary<HttpActionDescriptor, IList<string>> NotNullParameterNames =
        new ConcurrentDictionary<HttpActionDescriptor, IList<string>> ();


    /// <summary>
    /// Occurs before the action method is invoked.
    /// </summary>
    /// <param name="actionContext">The action context.</param>
    public override void OnActionExecuting (HttpActionContext actionContext)
    {
        var not_null_parameter_names = GetNotNullParameterNames (actionContext);
        foreach (var not_null_parameter_name in not_null_parameter_names)
        {
            object value;
            if (!actionContext.ActionArguments.TryGetValue (not_null_parameter_name, out value) || value == null)
                actionContext.ModelState.AddModelError (not_null_parameter_name, "Parameter \"" + not_null_parameter_name + "\" was not specified.");
        }


        if (actionContext.ModelState.IsValid == false)
            actionContext.Response = actionContext.Request.CreateErrorResponse (HttpStatusCode.BadRequest, actionContext.ModelState);
    }


    private static IList<string> GetNotNullParameterNames (HttpActionContext actionContext)
    {
        var result = NotNullParameterNames.GetOrAdd (actionContext.ActionDescriptor,
                                                     descriptor => descriptor.GetParameters ()
                                                                             .Where (p => !p.IsOptional && p.DefaultValue == null &&
                                                                                          !p.ParameterType.IsValueType &&
                                                                                          p.ParameterType != typeof (string))
                                                                             .Select (p => p.ParameterName)
                                                                             .ToList ());

        return result;
    }
}

And I put it in global filter for all Web API actions:

config.Filters.Add (new ValidateModelAttribute ());

Answer 3

This happened to me, and in my case, I had to change using Microsoft.Build.Framework; to using System.ComponentModel.DataAnnotations; (and add the reference).

Answer 4

this issue happened to me .i do not know why but take it easy just change your action Object name(UserCreate User) by some other like (UserCreate User_create)