Question

可以反过来使用实体框架方法DbPropertyValues.SetValues来设置对象的值，即视图模型或数据传输对象，基于实体中属性的当前值吗？

这是我如何将SetValues与DTO一起使用以仅更新我在DTO的类定义中指定的属性的一个示例。

public Address UpdateAddress(Address address)
{
    using (var context = new OrdersContext())
    {
        var targetAddress = context.Addresses.FirstOrDefault(a => a.AddressID == address.AddressID && a.User.UserName.ToLower() == HttpContext.Current.User.Identity.Name.ToLower());

        if (targetAddress == null) return null; // Address not found or user doesn't own this address.

        context.Entry(targetAddress).CurrentValues.SetValues(address);
        context.SaveChanges();

        return new Address
        {
            AddressID = targetAddress.AddressID,
            AddressLine1 = targetAddress.AddressLine1,
            AddressLine2 = targetAddress.AddressLine2,
            City = targetAddress.City,
            State = targetAddress.State,
            ZipCode = targetAddress.ZipCode
        };
    }
}

public class Address
{
    public int AddressID { get; set; }
    public string AddressLine1 { get; set; }
    public string AddressLine2 { get; set; }
    public string City { get; set; }
    public string State { get; set; }
    public string ZipCode { get; set; }
    // public string UserID { get; set; } // UserID is excluded from the view model so that it cannot be updated.
}

正如SetValues上的文件所示

给定对象可以是任何类型。对象上的任何属性都带有与字典中的属性名称匹配且可以读取的名称，将被阅读。其他属性将被忽略。这允许复制简单数据传输对象（DTO）的属性。

可以反向使用SetValues来设置实体的DTO值，以便不必逐个手动设置值吗？或者是否有另一种方法可以像SetValues一样工作但反过来？

还有另一个DbPropertyValues method called ToObject，但它不适用于DTO。

我想做这样的事情：

public Address UpdateAddress(Address address)
{
    using (var context = new OrdersContext())
    {
        var targetAddress = context.Addresses.FirstOrDefault(a => a.AddressID == address.AddressID && a.User.UserName.ToLower() == HttpContext.Current.User.Identity.Name.ToLower());

        if (targetAddress == null) return null; // Address not found or user doesn't own this address.

        context.Entry(targetAddress).CurrentValues.SetValues(address);
        context.SaveChanges();

        return context.Entry(targetAddress).ToObject(new Address());
    }
}

谢谢！

是否可以反向使用DbPropertyValues.SetValues从实体的当前值填充DTO？

0 个答案: