Return type for a List

Question

Hi I need to find a way to declare an anonymous type for a method.This is my code:

public List<var> ListOfProducts(string subcategory)
{
    var products = (from p in dataContext.Products
                    join s in dataContext.SubCategories.Where(x => x.SubCatName == subcategory)
                        on p.SubcatId equals s.SubCatId
                    join b in dataContext.Brands on p.BrandId equals b.BrandId
                    select new
                    {
                        Subcategory = s.SubCatName,
                        Brand = b.BrandName,
                        p.ProductName,
                        p.ProductPrice
                    });
    return products;
} 

I don't know what type should I set the List for the method.What should I do in this case?

Answer 1

You can't return an Anonymous Type from a method.

Just create a class for your type and return that.

public class Product
{
    string Subcategory { get; set; }
    string Brand { get; set; }
    string ProductName { get; set; }
    decimal ProductPrice { get; set; }
}

Then return as such:

var products = (from p in dataContext.Products
                    join s in dataContext.SubCategories.Where(x => x.SubCatName == subcategory) on p.SubcatId
                        equals s.SubCatId
                    join b in dataContext.Brands on p.BrandId equals b.BrandId
                    select new Product
                               {
                                   Subcategory = s.SubCatName,
                                   Brand = b.BrandName,
                                   p.ProductName,
                                   p.ProductPrice
                               });

    return products;

EDIT: To clarify my first statement, as @JamesMichaelHare points out, technically it is possible to return an anonymous type from a method by returning object or dynamic, but it's probably more hassle than it's worth since you'd have to use Reflection or some other way of accessing the properties of your object.

Answer 2

As per MSDN, The dynamic type enables the operations in which it occurs to bypass compile-time type checking. Instead, these operations are resolved at run time.

So Try this instead :

public IEnumerable<dynamic> ListOfProducts(string subcategory) 

Answer 3

What I would say, you should define another model for this, if you use returned result for Presentation layer, you should define ViewModel, or if you use for distribution layer, you can define as Dto object

public class ProductDto
{
    public string Subcategory {get; set; }
    public string Brand { get; set; }
    public string ProductName{ get; set; }
    public decimal ProductPrice{ get; set; }
}