[英]AutoMapper Map to different type based on an enum?
我开始实现AutoMapper ,首先我设法将它与Castle.Windsor集成,我已经在使用它了。 现在我有一个Post
实体,我想映射到LinkPostModel
或ImagePostModel
。 两者都继承自PostModel
1)这是我到目前为止:
public class PostModelFromPostEntityConverter : ITypeConverter<Post, PostModel>
{
private readonly IPostService postService;
public PostModelFromPostEntityConverter(IPostService postService)
{
if (postService == null)
{
throw new ArgumentNullException("postService");
}
this.postService = postService;
}
public PostModel Convert(ResolutionContext context)
{
Post post = (Post)context.SourceValue;
Link link = post.Link;
if (link.Type == LinkType.Html)
{
return new LinkPostModel
{
Description = link.Description,
PictureUrl = link.Picture,
PostId = post.Id,
PostSlug = postService.GetTitleSlug(post),
Timestamp = post.Created,
Title = link.Title,
UserMessage = post.UserMessage,
UserDisplayName = post.User.DisplayName
};
}
else if (link.Type == LinkType.Image)
{
return new ImagePostModel
{
PictureUrl = link.Picture,
PostId = post.Id,
PostSlug = postService.GetTitleSlug(post),
Timestamp = post.Created,
UserMessage = post.UserMessage,
UserDisplayName = post.User.DisplayName
};
}
return null;
}
}
显然,实现AutoMapper的重点是删除这样的重复代码,所以在添加自定义规则(例如if子句)之前,我应该如何映射常见的东西?
理想情况下,我希望这是这样的:
public class PostModelFromPostEntityConverter : ITypeConverter<Post, PostModel>
{
[...]
public PostModel Convert(ResolutionContext context)
{
Post post = (Post)context.SourceValue;
Link link = post.Link;
if (link.Type == LinkType.Html)
{
return Mapper.Map<Post, LinkPostModel>(post);
// and a few ForMember calls?
}
else if (link.Type == LinkType.Image)
{
return Mapper.Map<Post, ImagePostModel>(post);
// and a few ForMember calls?
}
return null;
}
}
2)完成此映射后。 我有一个“父”映射,我需要映射IEnumerable<Post>
以下模型:
public class PostListModel : IHasOpenGraphMetadata
{
public OpenGraphModel OpenGraph { get; set; } // og:model just describes the latest post
public IList<PostModel> Posts { get; set; }
}
所以基本上我需要另一个TypeConverter
(对吧?) ,它允许我先映射帖子列表,然后创建og:model
我有这个,但感觉有点笨重,我觉得它可能会更好:
public class PostListModelFromPostEntityEnumerableConverter : ITypeConverter<IEnumerable<Post>, PostListModel>
{
public PostListModel Convert(ResolutionContext context)
{
IEnumerable<Post> posts = (IEnumerable<Post>)context.SourceValue;
PostListModel result = new PostListModel
{
Posts = posts.Select(Mapper.Map<Post, PostModel>).ToList()
};
Post first = posts.FirstOrDefault();
result.OpenGraph = Mapper.Map<Post, OpenGraphModel>(first);
return result;
}
}
3)我实际上还没有运行代码,所以想到另一个问题,这就是为什么转换器中没有强映射的映射?
IEnumerable<Post> posts = (IEnumerable<Post>)context.SourceValue;
实际上它可能在哪里
IEnumerable<Post> posts = context.SourceValue;
试图获得死灵法师徽章。
现在,使用ConstructUsing
函数可以更容易地解决此任务。应该在提供的操作中填充特定字段,但所有常用字段都将转到ForMember
执行映射。 在这种情况下,集合不需要任何其他逻辑/映射配置。 具有类型集合属性的类。
cfg.CreateMap<Post, PostModel>()
.ConstructUsing(p =>
{
switch (p.Type)
{
case LinkType.Html: return new LinkPostModel
{
Title = p.Description
// other specific fields
};
case LinkType.Image: return new ImagePostModel
{
// other specific fields
};
}
return null;
})
.ForMember(x => x.PostId, m => m.MapFrom(p => p.Id));
cfg.CreateMap<PostList, PostListModel>();
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.