Automapper with linq how?

问题

Ok, I'm really struggling with finding a good example of what I need to do. So, I'll ask here.

Let's say I have a entity class (EF) named Customer and a corresponding view-model class named CustomerViewModel.

Using AutoMapper, I have created the following mappings:

 Mapper.CreateMap<CustomerViewModel, Customer>(); 
 Mapper.CreateMap<Customer, CustomerViewModel>();

How would I modify the following code to make use of this mapping?

    public static List<CustomerViewModel> GetCustomers()
    {
        using (var context = new GCSBaseEntities())
        {
            var query = from c in context.Customers
                        select new CustomerViewModel
                        {
                            CompanyName = c.CompanyName,
                            Id = c.Id,
                            EmailAddress = c.EmailAddress,
                            FirstName = c.FirstName,
                            LastName = c.LastName,
                            MiddleName = c.MiddleName,
                            ModifiedDate = c.ModifiedDate,
                            Phone = c.Phone,
                            SalesPerson = c.SalesPerson,
                            Suffix = c.Suffix,
                            Title = c.Title,
                            FullName = c.FirstName + " " + c.LastName
                        };

            return query.ToList();
        }
    }

Thanks in advance.

回答1:

When you register your mappings, you must provide any complex mapping operations that have to occur. In your case, I believe all your properties match up, except for FullName = c.FirstName + " " + c.LastName. Here's how your Customer-to-CustomerViewModel mapping should look:

Mapper.CreateMap<Customer, CustomerViewModel>()
       .ForMember(custVm => custVm.FullName,
            mapper => mapper.MapFrom(cust => cust.FirstName + " " + cust.LastName));

You'll have to figure out how to shove the FullName prop from the ViewModel back into the FirstName & LastName fields on the EF class, though. But when you decide how to implement it, follow the pattern from above for the other mapping.

Your query can now be MUUUCH smaller:

using (var context = new GCSBaseEntities()) 
{
     return from c in context.Customers
            select Mapper.Map<CustomerViewModel>(c);
}

回答2:

Figured it out. In order to avoid the aforementioned error, you have to Add the call the .AsEnumerable() after Customers like so:

     return from c in context.Customers.AsEnumerable()
        select Mapper.Map<CustomerViewModel>(c);

I got this from this thread: LINQ and AutoMapper

来源：https://stackoverflow.com/questions/20223995/automapper-with-linq-how

标签

linq

entity-framework-5

automapper-3