Question

public partial class Product
{
    public Product()
    {
        this.ProductPrimaryPrices = new HashSet<ProductPrimaryPrice>();
        this.ProductSecondaryPrices = new HashSet<ProductSecondaryPrice>();            
    }

    public int ProductId { get; set; }       
    public string Code { get; set; }
    public string Name { get; set; }
    public string Description { get; set; }
    public byte[] Image { get; set; }        

    public virtual ICollection<ProductPrimaryPrice> ProductPrimaryPrices { get; set; }        
    public virtual ICollection<ProductSecondaryPrice> ProductSecondaryPrices { get; set; }
}

从上面的代码中，我只想选择ProductId实体的Code，Name，Description和Product以及{的所有相关属性{1}}和ProductPrimaryPrices，因为从数据库加载Image ProductSecondaryPrice数组需要花费很多时间。我只需要byte[]实体中的所选列以及Product和ProductPrimaryPrice中的所有列。

我已经尝试过如下所示的匿名类型，但在如何将匿名类型再次转换回ProductSecondaryPrices方面却苦苦挣扎。

Product

任何人都可以帮助我吗？

Answer 1

最后，我在一些头脑风暴后得到了答案

现在，我可以使用反射将匿名类型转换为Product类型。我已经实现了一种将匿名类型转换为＆＃39; Product＆＃39;类型然后逐个我循环匿名类型并通过调用新实现的方法将其转换为Product类型。

以下是实施

public List<Product> GetProduct()
{
    List<Product> products = new List<Product>();
    using (var ctx = new PosEntities())
    {
        var tempProducts = 
            (from p in ctx.Products.Include("ProductPrimaryPrices").Include("ProductSecondaryPrices").Include("ProductsModifiers")
            where (p.MenuGroupId == menuGroupId && p.Active) && (p.ProductPrimaryPrices.Any(x => x.OutletId == outletId && x.Active))
            select new 
            {
                ProductId = p.ProductId,
                Code = p.Code,
                Name = p.Name,
                Description = p.Description,                
                ProductPrimaryPrices = p.ProductPrimaryPrices,
                ProductSecondaryPrices = p.ProductSecondaryPrices,
                ProductsModifiers = p.ProductsModifiers
            }).ToList();                    

        foreach (object anonymous in tempProducts)
        {
            Product product = (Product)Utility.ToType<Product>(anonymous, new Product());
            products.Add(product);
        }
        return products;
    }
}

以下是将匿名类型转换为Product类型

的方法

public static class Utility
    {
        public static object ToType<T>(this object obj, T type)
        {
            //create instance of T type object:            
            object tmp = Activator.CreateInstance(Type.GetType(type.ToString()));

            //loop through the properties of the object you want to covert:          
            foreach (PropertyInfo pi in obj.GetType().GetProperties())
            {
                try
                {
                    //get the value of property and try to assign it to the property of T type object:
                    tmp.GetType().GetProperty(pi.Name).SetValue(tmp, pi.GetValue(obj, null), null);
                }
                catch (Exception ex)
                {
                    // Logging.Log.Error(ex);
                }
            }
            //return the T type object:         
            return tmp;
        }       
    }

如何在Linq中仅选择主表的选定列和详细表的所有列

1 个答案: