使用抽象类型的反射从表中获取实体 [英] Get Entity From Table Using Reflection From Abstract Type
问题描述
好的,所以我有一个名为 Product 的抽象类.我有 3 个表,称为 Items、Kits 和 Packages,它们实现了 Product.产品具有公开对象的主键的公共属性.
Ok, so I have an abstract class called Product. I have 3 tables called Items, Kits, and Packages that implement Product. Product has a public property that exposes the object's primary key.
也就是说我有一个表格,我可以在其中传递产品.我想将该产品从新的数据上下文中提取出来,而不必编写反映其类型的大开关来获取其正确的表.
That said I have a form where I pass a product. I would would like to pull that product out of a fresh datacontext without having to write a big switch reflecting it's type to get its proper table.
我想做这样的事情,但演员表不接受 foo.
I wanted to do something like this but the cast bit won't accept foo.
public BuilderInclusionsForm(Product p) : this()
{
Type foo = p.GetType();
product = db2.GetTable(p.GetType()).Cast<foo>().SingleOrDefault(a =>
a.ProductID == p.ProductID);
或者这个:
public BuilderInclusionsForm(Product p) : this()
{
Type foo = p.GetType();
product = db2.GetTable(p.GetType()).OfType<foo>().SingleOrDefault(a =>
a.ProductID == p.ProductID);
推荐答案
感谢 Skeet 先生,我团队中一位聪明的成员指出了以下解决方案.
With thanks to Mr. Skeet a bright member of my team pointed out the following solution.
public BuilderInclusionsForm(Product p) : this()
{
IEnumerable<Product> ps = db2.GetTable(p.GetType()).Cast<Product>();
product = ps.SingleOrDefault(a => a.ProductID == p.ProductID);
}
很抱歉浪费您的时间.请不要垃圾收集我对不起的屁股约翰.=oD
Sorry to waste your time. Please don't garbage collect my sorry ass John. =oD
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