c# - AutoMapper:领域模型和 View 模型之间的双向深度映射

Question

我需要在平面 ViewModel 和深度结构化域模型之间映射两种方式。这将是我们解决方案中的常见场景。

我的模型是:

public class Client 
{
   ...
   public NotificationSettings NotificationSettings { get; set; }
   public ContactDetails ContactDetails { get; set; }
   ...
}

public class NotificationSettings
{
    ...
    public bool ReceiveActivityEmails { get; set; }
    public bool ReceiveActivitySms { get; set; }
    ...
}

public class ContactDetails
{
    ...
    public string Email { get; set }
    public string MobileNumber { get; set; }
    ...
}

public class ClientNotificationOptionsViewModel
{
    public string Email { get; set }
    public string MobileNumber { get; set; }
    public bool ReceiveActivityEmails { get; set; }
    public bool ReceiveActivitySms { get; set; }
}

映射代码:

Mapper.CreateMap<Client, ClientNotificationOptionsViewModel>()
    .ForMember(x => x.ReceiveActivityEmails, opt => opt.MapFrom(x => x.NotificationSettings.ReceiveActivityEmails))
    .ForMember(x => x.ReceiveActivitySms, opt => opt.MapFrom(x => x.NotificationSettings.ReceiveActivitySms))
    .ForMember(x => x.Email, opt => opt.MapFrom(x => x.ContactDetails.Email))
    .ForMember(x => x.MobileNumber, opt => opt.MapFrom(x => x.ContactDetails.MobileNumber));

// Have to use AfterMap because ForMember(x => x.NotificationSettings.ReceiveActivityEmail) generates "expression must resolve to top-level member" error
Mapper.CreateMap<ClientNotificationOptionsViewModel, Client>()
    .IgnoreUnmapped()
    .AfterMap((from, to) =>
    {
        to.NotificationSettings.ReceiveActivityEmail = from.ReceiveActivityEmail;
        to.NotificationSettings.ReceiveActivitySms = from.ReceiveActivitySms;
        to.ContactDetails.Email = from.Email;
        to.ContactDetails.MobileNumber = from.MobileNumber;
    });


...

// Hack as ForAllMembers() returns void instead of fluent API syntax
public static IMappingExpression<TSource, TDest> IgnoreUnmapped<TSource, TDest>(this IMappingExpression<TSource, TDest> expression)
{
    expression.ForAllMembers(opt => opt.Ignore());
    return expression;
}

我不喜欢它是因为:

1)很麻烦

2) 第二个映射几乎取消了 Automapper 的功能并手动实现工作 - 它的唯一优点是在整个代码中引用 Automapper 的一致性

任何人都可以建议:

a) 将 Automapper 用于深层属性的更好方法？

b) 像这样执行双向映射的更好方法？

c) 关于在这种情况下我是否应该费心使用 Automapper 的建议？是否有令人信服的理由不恢复到手动编码的更简单方法？例如:

void MapManually(Client client, ClientNotificationOptionsViewModel viewModel)
{
    viewModel.Email = client.ContactDetails.Email;
    // etc
}  

void MapManually(ClientNotificationOptionsViewModel viewModel, Client client)
{
    client.ContactDetails.Email = viewModel.Email;
    // etc
}

-布伦丹

附言重构领域模型不是解决方案。

P.P.S 可以通过扩展方法和一些时髦的反射来设置深层属性来清理上面的代码......但如果可能的话我宁愿使用自动映射器功能。

Answer 1

这也可以通过这种方式完成:

Mapper.CreateMap<ClientNotificationOptionsViewModel, Client>()
    .ForMember(x => x.NotificationSettings, opt => opt.MapFrom(x => new NotificationSettings() { ReceiveActivityEmails = x.ReceiveActivityEmails, ReceiveActivitySms = x.ReceiveActivitySms}))
    .ForMember(x => x.ContactDetails, opt => opt.MapFrom(x => new ContactDetails() { Email = x.Email, MobileNumber = x.MobileNumber }));

但与您的解决方案没有太大区别。

此外，您还可以通过创建从您的模型到您的内部类的映射来做到这一点:

Mapper.CreateMap<ClientNotificationOptionsViewModel, ContactDetails>();

Mapper.CreateMap<ClientNotificationOptionsViewModel, NotificationSettings>();

Mapper.CreateMap<ClientNotificationOptionsViewModel, Client>()
    .ForMember(x => x.NotificationSettings, opt => opt.MapFrom(x => x))
    .ForMember(x => x.ContactDetails, opt => opt.MapFrom(x => x));

您不需要在新映射中指定 ForMember，因为属性在两个类中具有相同的名称。