Automapper，将单个目标属性映射为多个源属性的串联

Question

我有一种情况，我需要根据某些条件将单个属性映射为多个源属性的组合。

目的地 :

public class Email
{
    public Email() {
        EmailRecipient = new List<EmailRecipient>();
    }
    public string Subject{get; set;}
    public string Body {get; set;}
    public virtual ICollection<EmailRecipient> EmailRecipient { get; set; } 
}

public class EmailRecipient
{
    public int EmaiId { get; set; }
    public string RecipientEmailAddress { get; set; }
    public int RecipientEmailTypeId { get; set; }
    public virtual Email Email { get; set; }
}

来源:

public class EmailViewModel
{
    public List<EmailRecipientViewModel> To { get; set; }
    public List<EmailRecipientViewModel> Cc { get; set; }
    public string Subject { get; set; }
    public string Body { get; set; }
}

public class EmailRecipientViewModel
{
    public string RecipientEmailAddress { get; set; }
}

我要 Mapper.Map<EmailViewModel,Email>()
在这里我想映射我的 Email.EmailRecipient作为 EmailViewModel.To 的组合和 EmailViewModel.Cc .
然而条件是， Email.EmailRecipient.RecipientEmailTypeId 为 1至 和 2 表示 抄送

希望我的问题很清楚。

Answer 1

实现此目的的一种可能方法是创建一个使用特定方法进行此转换的 map 。 map 创建将是:

Mapper.CreateMap<EmailViewModel, Email>()
    .ForMember(e => e.EmailRecipient, opt => opt.MapFrom(v => JoinRecipients(v)));

凡 JoinRecipients方法将执行转换本身。一个简单的实现可能是这样的:

private ICollection<EmailRecipient> JoinRecipients(EmailViewModel viewModel) {
    List<EmailRecipient> result = new List<EmailRecipient>();
    foreach (var toRecipient in viewModel.To) {
        result.Add(new EmailRecipient {
            RecipientEmailTypeId = 1, 
            RecipientEmailAddress = toRecipient.RecipientEmailAddress
        });
    }

    foreach (var ccRecipient in viewModel.Cc) {
        result.Add(new EmailRecipient {
            RecipientEmailTypeId = 2,
            RecipientEmailAddress = ccRecipient.RecipientEmailAddress
        });
    }

    return result;
}