问ASP.NET MVC，对象，多个构造函数的每个请求一个实例

EN

public class SiteModule : NinjectModule
{
    public override void Load() {        
       Bind<IUnitOfWork>().To<SqlUnitOfWork>()
                          .InRequestScope()
                          .WithConstructorArgument("connectionString", ConfigurationManager.ConnectionStrings["Entities"].ConnectionString);

       Bind<IProductRepository>().To<ProductRepository>();
       Bind<ICategoryRepository>().To<CategoryRepository>();
    }
}

public class ProductRepository {
    IUnitOfWork unitOfWork;
    public ProductRepository(IUnitOfWork unitOfWork) {
        this.unitOfWork = unitOfWork;
    }
}

public class CategoryRepository {
    IUnitOfWork unitOfWork;
    public CategoryRepository(IUnitOfWork unitOfWork) {
        this.unitOfWork = unitOfWork;
    }
}