entity-framework - EF4 如何在 LINQ 中将匿名类型转换为强类型

Question

LINQ 代码返回匿名类型如何返回强类型的“客户”？
我正在返回一个匿名类型，因为我只想从实体中选择某些字段。

var customer = from c in _entities.Customers
                           join con
                           in _entities.Contracts on c.CustomerID equals con.customerID
                           where con.contractNo == number
                           select new
                           {
                               Surname = c.Surname,
                               Forename= c.Forename,
                               Address = c.Address,
                               Suburb = c.Suburb,
                               State = c.State,
                               Postcode = c.PostCode,
                               PhoneNo = c.PhoneNo
                       };

谢谢

Answer 1

要么做

var customer = from c in _entities.Customers
                       join con
                       in _entities.Contracts on c.CustomerID equals con.customerID
                       where con.contractNo == number
                       select c;

按原样选择客户实例或

Customer customer = (from c in _entities.Customers
                       join con
                       in _entities.Contracts on c.CustomerID equals con.customerID
                       where con.contractNo == number
                       select new Customer{
                           Surname = c.Surname,
                           Forename= c.Forename,
                           Address = c.Address,
                           Suburb = c.Suburb,
                           State = c.State,
                           Postcode = c.PostCode,
                           PhoneNo = c.PhoneNo
                       }).FirstOrDefault();

仅填写您感兴趣的属性来创建客户的新实例。 (提供的客户类有一个无参数的构造函数)