Question

我想初始化列表，并根据某些值使此列表具有一种特殊的类型，这是我创建的模型。我不知道我是否解释得很好-我的代码在下面

public static List<someModeltypeAorBorC> SomeMethod()
{
    var list = new List<dynamic>();
    if (Val == "A")
    {
        List<ModelA> list = new List<ModelA>();
    }
    else if (Val == "B")
    {
        List<ModelB> list = new List<ModelB>();
    }
    else if (Val == "C")
    {
        List<ModelC> list = new List<ModelC>();
    }
}

我想在范围之外初始化列表，以便可以在下一步中使用。您也可以看到，我必须返回此列表。可能吗？我将不胜感激！

Answer 1

您可以尝试：

SELECT customer_brandids.brand_id, brands.brand_id, customer_brandids.customer_id, brands.brand_name
    FROM 
        (SELECT customer_receipts.receipt_id, receipt_item_details1.receipt_id, customer_receipts.customer_id, receipt_item_details1.brand_id
        FROM
            (SELECT receipts.customer_id, customers.customer_id, receipts.receipt_id
            FROM receipts
            INNER JOIN customers
            ON receipts.customer_id = customers.customer_id) AS customer_receipts
        INNER JOIN receipt_item_details1
        ON customer_receipts.receipt_id = receipt_item_details1.receipt_id) AS customer_brandids
    INNER JOIN brands
    ON customer_brandids.brand_id = brands.brand_id

Answer 2

谢谢大家的回答。我最后要做的是创建其他Model A.B和C继承的Model类。在方法中，我添加了行

   List<Model> list = new List<Model>();

我返回List，当我需要访问下层阶级的属性时，我正在使用

List<Model> obj = List<Model>; 
obj = SomeMethod() //which return object of ModelA.B or C
((ModelA)obj).PropoertyOfModelA // reach the property specified model

在没有类型C＃

2 个答案: