How to use Automapper to create complex viewmodel objects from a simple object and a method call

问题:

My application needs to display a table of customer data, including data about the customer and about his most recent order from a given warehouse. The customer domain object contains a GetLatestOrder(warehouseId) method.

I have a CustomerView viewmodel and want to be able to populate it with some fields from the customer object, and a few fields from the latest order object. Can I do this using Automapper?

回答1:

Try this,

In Global.asax.cs [Application_Start], public static void AppInitialize()

    protected void Application_Start(object sender, EventArgs e)     {         Mapper.CreateMap()              .ForMember(destination => destination.OrderId, options => options.MapFrom(source => source.Id))              .ForMember(destination => destination.OrderName, options => options.MapFrom(source => source.Name));         Mapper.CreateMap()              .ForMember(destination => destination.CustmerId, options => options.MapFrom(source => source.Id))              .ForMember(destination => destination.CustmerName, options => options.MapFrom(source => source.Name))              .ForMember(destination => destination.OrderId, options => options.MapFrom(source => Mapper.Map, IEnumerable>(source.Orders).FirstOrDefault().OrderId))              .ForMember(destination => destination.OrderName, options => options.MapFrom(source => Mapper.Map, IEnumerable>(source.Orders).FirstOrDefault().OrderName));     } 

And in your code call the mapper like below,

        var lstCustomers = new List         {             new Customer { Id = 1, Name="Name", Orders = new List { new Order { Id = 1000, Name ="Some Name"}}},         };          var result = Mapper.Map, IEnumerable>(lstCustomers); 

I am presumed that you classes looks like below,

public class Customer {     public int Id { get; set; }     public string Name { get; set; }     public List Orders { get; set; } }  public class Order {     public int Id { get; set; }     public string Name { get; set; } }  public class CustomerViewModel {     public int CustmerId { get; set; }     public string CustmerName { get; set; }     public int OrderId { get; set; }     public string OrderName { get; set; } } 

Also refer this post.

回答2:

Yes, you can:

var vm = new CustomerViewModel(); Mapper.Map(customer, vm); Mapper.Map(order, vm); 

Each mapping will populate the properties it is configured to and leave the rest.

回答3:

In the end, I took the easy approach, couldn't find another way:

In Application_start:

    Mapper.CreateMap();     Mapper.CreateMap(); 

In the controller method:

    IEnumerable customers = GetCustomers(false)                                                .OrderBy(c => c.Name);     IEnumerable viewData = Mapper.Map, IEnumerable>(customers);     foreach (Customer customer in customers)     {         CustomerView view = viewData.Where(cv => cv.CustomerId == customer.CustomerId).First();         Mapper.Map(customer.GetLatestOrder(WarehouseId), view);     } 

文章来源: How to use Automapper to create complex viewmodel objects from a simple object and a method call