[英]C# Automapper "Unsupported Mapping" with List<dynamic> result of LinQ query
Given the next working LinQ query:鉴于下一个工作 LinQ 查询:
var catalogues = (from cat in db.CATALOGUES
join doc in db.DOCUMENTS_CATALOGS on
new { a = cat.PFK_ENTERPRISE, b = cat.FK_DOCUMENT_VIDEO }
equals
new { a = doc.PFK_ENTERPRISE, b = (int?)doc.PK_DOCUMENT }
join pos in db.DOCUMENTS_CATALOGS on
new { a = cat.PFK_ENTERPRISE, b = cat.FK_DOCUMENT }
equals
new { a = pos.PFK_ENTERPRISE, b = (int?)pos.PK_DOCUMENT }
where (cat.PFK_ENTERPRISE == enterpriseId && cat.PK_CATALOGUE == catalogueId)
orderby cat.DESC_CATALOGUE ascending
select new
{
cat.PK_CATALOGUE,
cat.FK_DOCUMENT_VIDEO,
cat.DESC_CATALOGUE,
doc.REAL_NAME,
doc.SERVER_NAME_ORIGINAL_FILE,
POSTER = pos.SERVER_NAME_ORIGINAL_FILE
});
Which produces a result with a List Anonymous with something like this (1 record un my case):这会产生一个带有类似这样的匿名列表的结果(我的情况下有 1 条记录):
{
PK_CATALOGUE = 212,
FK_DOCUMENT_VIDEO = 212,
DESC_CATALOGUE = "xxx",
REAL_NAME = "7_Category_Image_c3ab57e3-ec7e-4a80-aaa1-c6cc10a1b917.jpg",
SERVER_NAME_ORIGINAL_FILE = "7_Category_Image_c3ab57e3-ec7e-4a80-aaa1-c6cc10a1b917.jpg",
POSTER = "7_IMG_CATALOGUE_5d8e24eb-8a40-4e4d-9d86-a3f610d5b65e.jpg"
}
I'm trying to map it to the next object:我正在尝试将 map 转换为下一个 object:
public class VideoGalleryVM
{
public int PK_CATALOGUE { get; set; }
public int? FK_DOCUMENT_VIDEO { get; set; }
public string DESC_CATALOGUE { get; set; }
public string REAL_NAME { get; set; }
public string SERVER_NAME_ORIGINAL_FILE { get; set; }
public string POSTER { get; set; }
}
The following way:以下方式:
var config = new MapperConfiguration(cfg =>
{
cfg.CreateMap<object, VideoTrainingVM>().ReverseMap();
});
IMapper mapper = config.CreateMapper();
List<VideoGalleryVM> vgVM = mapper.Map<List<VideoGalleryVM>>(videoGallery);
But I whatever I try I get an exception of type "Invalid mapping".但是无论我尝试什么,我都会遇到“无效映射”类型的异常。
I don't mind using Automapper or not, just need to cast the return of the LinQ query (that is List dynamic) to a View Model object, and:我不介意使用 Automapper,只需要将 LinQ 查询(即动态列表)的返回值转换为视图 Model object,并且:
var test1 = catalogues.ToList().Cast<VideoGalleryVM1>().ToList();
ends with an invalid cast Exception and以无效的强制转换异常结束,并且
var test2 = catalogues.OfType<VideoGalleryVM1>().ToList();
ends with a list of 0 elements.以 0 个元素的列表结尾。
You do not need Automapper for everything, it was created for simple scenarios - mapping similar KNOWN objects to another and better if mapping is simple.您不需要所有的 Automapper,它是为简单的场景创建的 - 将相似的 KNOWN 对象映射到另一个对象,如果映射简单,则更好。 If you make projection via
Select
- you can map all that you need in one place without using "magic" of Automapper.如果您通过
Select
进行投影 - 您可以 map 将您需要的所有东西集中在一个地方,而无需使用 Automapper 的“魔法”。
So just project your result into desired objet type:因此,只需将您的结果投影到所需的对象类型中:
var catalogues =
from cat in db.CATALOGUES
join doc in db.DOCUMENTS_CATALOGS on
new { a = cat.PFK_ENTERPRISE, b = cat.FK_DOCUMENT_VIDEO }
equals
new { a = doc.PFK_ENTERPRISE, b = (int?)doc.PK_DOCUMENT }
join pos in db.DOCUMENTS_CATALOGS on
new { a = cat.PFK_ENTERPRISE, b = cat.FK_DOCUMENT }
equals
new { a = pos.PFK_ENTERPRISE, b = (int?)pos.PK_DOCUMENT }
where (cat.PFK_ENTERPRISE == enterpriseId && cat.PK_CATALOGUE == catalogueId)
orderby cat.DESC_CATALOGUE ascending
select new VideoGalleryVM
{
PK_CATALOGUE = cat.PK_CATALOGUE,
FK_DOCUMENT_VIDEO = cat.FK_DOCUMENT_VIDEO,
DESC_CATALOGUE = cat.DESC_CATALOGUE,
REAL_NAME = doc.REAL_NAME,
SERVER_NAME_ORIGINAL_FILE = doc.SERVER_NAME_ORIGINAL_FILE,
POSTER = pos.SERVER_NAME_ORIGINAL_FILE
};
Highly recommend to read article from Automapperr's creator when to use or not his library.强烈建议阅读 Automapperr 的创建者何时使用或不使用他的库的文章。 Article was created to stop using library for cases when it is a pain to support mapping later: AutoMapper Usage Guidelines
创建文章是为了在以后支持映射很痛苦的情况下停止使用库: AutoMapper 使用指南
The only solution I've found to cast my List of dynamic (result of LinQ query) to a View Model object was:我发现将我的动态列表(LinQ 查询的结果)转换为视图 Model object 的唯一解决方案是:
var targetList = catalogues.Select(cat => new VideoGalleryVM()
{
PK_CATALOGUE = cat.PK_CATALOGUE,
FK_DOCUMENT_VIDEO = cat.FK_DOCUMENT_VIDEO,
DESC_CATALOGUE = cat.DESC_CATALOGUE,
REAL_NAME = cat.REAL_NAME,
SERVER_NAME_ORIGINAL_FILE = cat.SERVER_NAME_ORIGINAL_FILE,
POSTER = cat.SERVER_NAME_ORIGINAL_FILE
}).ToList();
I don't think is the best option, not even understand why Automapper (or other type of casts) won't work, but this just works.我不认为是最好的选择,甚至不明白为什么 Automapper(或其他类型的演员表)不起作用,但这只是工作。
In my case we are talking of a class with not so many properties, but image a long class... this is what Automapper is supposed to.在我的例子中,我们谈论的是一个没有那么多属性的 class,但图像是一个长的 class ......这就是 Automapper 应该做的。
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