AspNet Core RC2 Model binding gives null model

Question

I am working with ASP.NET CORE RC2 and I have the following model binder:

public class MovieModelBinder : IModelBinder
{
    public Task BindModelAsync(ModelBindingContext bindingContext)
    {
        if (bindingContext.ModelType == typeof(MovieViewModel))
        {
            var idValue = bindingContext.ValueProvider.GetValue("Id").FirstValue;
            var nameValue = bindingContext.ValueProvider.GetValue("Name").FirstValue;

            var timespanProperty = bindingContext.ModelMetadata.Properties.Single(p => p.PropertyName == "Length");
            var timespanValue = bindingContext.ValueProvider.GetValue(timespanProperty.PropertyName).FirstValue;

            int minutes;
            int.TryParse(timespanValue, out minutes);

            int id;
            int.TryParse(idValue, out id);

            var model = new MovieViewModel
            {
                Length = TimeSpan.FromMinutes(minutes),
                Id = id,
                Name = nameValue
            };

            return Task.FromResult(ModelBindingResult.Success(bindingContext.ModelName, model));
        }

        return Task.FromResult(default(ModelBindingResult));
    }
}

I am using it on a controller action like this:

[HttpPost]
public IActionResult Create([ModelBinder(BinderType = typeof(MovieModelBinder))] MovieViewModel model)
{
    // Code here
}

Problem is that I get a null model every time. What is exactly wrong with the ModelBindingResult.Success method and what change should be made to return correct results?

Answer 1

I'm not sure whats wrong, for me same code stopped working after rc2 update.

For workaround just manually assign :

bindingContext.Result = ModelBindingResult.Success(bindingContext.ModelName, model); 

before

return Task.FromResult(...)