List的返回类型

Question

嗨,我需要找到一种方法来声明一个方法的匿名类型.这是我的代码:

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;
} 

我不知道我应该为该方法设置List的类型.在这种情况下我该怎么办？

Answer 1

您无法Anonymous Type从方法返回.

只需为您的类型创建一个类并返回该类.

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

然后返回:

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;

编辑:为了澄清我首先声明,如@JamesMichaelHare指出,在技术上有可能通过返回返回从一个方法匿名类型object或dynamic,但它可能是更多的麻烦比它的价值,因为你不得不使用Reflection或某种其他方式访问对象的属性.

Answer 2

根据MSDN,动态类型使其发生的操作能够绕过编译时类型检查.相反,这些操作在运行时解决.

所以试试这个:

public IEnumerable<dynamic> ListOfProducts(string subcategory)