使用AutoMapper进行条件投影

Question

假设我在'Message'类上有一个'Comment'属性.我还有2个具有'Body'属性的类属性.如果类具有任何类属性集,我希望AutoMapper将Body属性投影到模型的comment属性中,否则在消息类上使用普通的comment属性.

例如

public class Message
{
     public string Comment { get; set; }
     public Inbound? InboundMessage { get; set; }
     public Outbound? OutboundMessage { get; set; }
}

public class Inbound
{
     public string Body { get; set; }
}

public class Outbound
{
     public string Body { get; set; }
}


public class MessageModel
{
     public string Comment { get; set; }
}

我没有在文档中看到任何处理此问题的内容.

Answer 1

使用ValueResolver:

.ForMember(dto => dto.Comment, opt => opt.ResolveUsing<CommentResolver>().FromMember(src => src))

然后实际实施:

public class CommentResolver: ValueResolver<Message, string>
{
    protected override string ResolveCore(Message msg)
    {
        //logic goes here
        if (msg.InboundMessage != null)
         return msg.InboundMessage.Body; 
        else if (msg.OutboundMessage != null)
         return msg.OutboundMessage.Body; 
       else
         return msg.Comment;

    }
}