c# – Mapper已初始化

我有一个3层架构Web Api解决方案,里面有3个项目：数据,业务和表示层.我需要在两个业务和表示层中初始化两个不同的映射器.

我已经创建了一个静态类和方法来初始化业务逻辑中的一个映射器：

using AutoMapper;using Shop.BLL.DTOModels;using Shop.DAL.Models;using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace Shop.BLL.InitMapper{    public static class InitializeMapperBLL    {        public static void RegisterMappings()        {            Mapper.Initialize(cfg => cfg.CreateMap<Category, DTOCategoryModel>());        }    }}

并称之为：

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;using Shop.DAL.Repositories;using AutoMapper;using Shop.BLL.DTOModels;using Shop.DAL.Models;using Shop.BLL.Interfaces;using Shop.DAL.Interfaces;using Shop.BLL.InitMapper;namespace Shop.BLL.Services{    public class CategoryService : ICategoryService    {        IUnitOfWork Database { get; set; }        public CategoryService(IUnitOfWork uow)        {            Database = uow;        }        public IEnumerable<DTOCategoryModel> GetCategories()        {//I call it here            InitializeMapperBLL.RegisterMappings();            return Mapper.Map<IEnumerable<Category>, List<DTOCategoryModel>>(Database.Categories.GetAll());        }        public void Dispose()        {            Database.Dispose();        }    }}

在表示层我做同样的事情：

using AutoMapper;using Shop.API.ViewModels;using Shop.BLL.DTOModels;using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace Shop.API.MapperInit{    public static class InitializeMapperAPI    {        public static void RegisterMappings()        {            Mapper.Initialize(cfg => cfg.CreateMap<DTOCategoryModel, CategoryViewModel>());        }    }}

并调用Global.asax

protected void Application_Start()        {            AreaRegistration.RegisterAllAreas();            GlobalConfiguration.Configure(WebApiConfig.Register);            FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);            RouteConfig.RegisterRoutes(RouteTable.Routes);            BundleConfig.RegisterBundles(BundleTable.Bundles);      //here I call it            InitializeMapperAPI.RegisterMappings();            CreateKernel();        }

我已经初始化了错误Mapper.您必须为每个应用程序域/进程调用一次Initialize.

如何解决这个问题呢？

解决方法:

您可以使用反射和自动播放器配置文件的一种方法.这在我用过的项目中非常有效.

在每个项目/图层中创建一个automapper配置文件类.每个配置文件类应仅包含它自己需要的映射.以下是其中一个的示例：

  //Profile here is of type AutoMapper.Profile  public class BusinessLayerMapperConfig : Profile  {    public BusinessLayerMapperConfig()    {      //create layer specific maps      CreateMap<MyObjectDTO, MyObjectViewModel>();    }    public override string ProfileName    {      get { return this.GetType().ToString(); }    }  }

然后真正靠近应用程序入口点的地方(我从Global.asax.cs中的ApplicationStart方法调用以下方法),初始化所有的配置文件,如下所示：

public static void RegisterMaps()    {      //get all projects' AutoMapper profiles using reflection      var assembliesToScan = System.AppDomain.CurrentDomain.GetAssemblies();      var allTypes = assembliesToScan.SelectMany(a => a.ExportedTypes).ToArray();      var profiles =          allTypes              .Where(t => typeof(Profile).GetTypeInfo().IsAssignableFrom(t.GetTypeInfo()))              .Where(t => !t.GetTypeInfo().IsAbstract);      //add each profile to our static AutoMapper      Mapper.Initialize(cfg =>      {        foreach (var profile in profiles)        {          cfg.AddProfile(profile);        }      });    }

这将允许您按照它们使用的图层逻辑分隔您的地图,并确保您只初始化它们一次.

来源：https://www.icode9.com/content-1-315301.html