public void Configuration(IApplicationBuilder app)
{
    ...
    HttpModelHandler.RegisterModelBinder<HttpMultipartFormModelBinder>();
    ...
    app.UseSimplifyWeb();
}

public void ConfigureServices(IServiceCollection services)
{
    ...
    DIContainer.Current.RegisterHttpMultipartFormModelBinder();
    ...
}

public class MyController : ControllerAsync<MultipartViewModel>
{
    public override async Task<ControllerResponse> Invoke()
    {
        await ReadModelAsync();

        Model.Files
    }
}

public class MyController : Controller<MultipartViewModel>
{
    public override ControllerResponse Invoke()
    {
        Model.Files
    }
}