Question

我有以下代码：

我的项目结构如下：

我的课程（与此错误相关）

SizeEntity.cs

namespace DataObjects.EntityFramework
{
    public class SizeEntity
    {
        public int Id { get; set; }
        public string SizeName { get; set; }
    }
}

Size.cs（在业务对象类库上）

namespace BusinessObjects
{

    // Product business object
    // ** Enterprise Design Pattern: Domain Model, Identity Field, Foreign key mapping

    public class Size : BusinessObject
    {
        // ** Enterprise Design Pattern: Identity field pattern
        public Size()
        {
            // establish business rules
            AddRule(new ValidateRequired("SizeName"));
            AddRule(new ValidateLength("SizeName", 1, 3));
        }

        public int Id { get; set; }
        public string SizeName { get; set; }

    }
}

SizeDao.cs

public class SizeDao : ISizeDao
    {
        /// <summary>
        /// Constructor to initialize AutoMapper
        /// </summary>
        static SizeDao()
        {
            Mapper.Initialize(cfg => cfg.CreateMap<SizeEntity, Size>());
            Mapper.Initialize(cfg => cfg.CreateMap<List<SizeEntity>, List<Size>>());
        }

        /// <summary>
        /// Inserts size into database
        /// </summary>
        /// <param name="size"></param>
        public void InsertSize(Size size)
        {
            using (var context = new ExamContext())
            {
                var entity = Mapper.Map<Size, SizeEntity>(size);

                context.Sizes.Add(entity);
                context.SaveChanges();

                // update business object with new id
                size.Id = entity.Id;
            }
        }

        /// <summary>
        /// Gets all size from database
        /// </summary>
        /// <returns>Returns a list of Sizes</returns>
        public List<Size> GetSizes()
        {
            using (var context = new ExamContext())
            {
                var sizes = context.Sizes.ToList();
                return Mapper.Map<List<SizeEntity>, List<Size>>(sizes);
            }
        }
    }

我在此代码的最后一行收到映射错误。

返回Mapper.Map，List＆gt;（sizes）;

我在这里缺少什么？

错误消息在标题中： AutoMapperMappingException：缺少类型映射配置或不支持的映射，映射类型列表

更新1：

我删除了该行建议并仍然获得：缺少类型映射配置或不支持的映射。

Mapping types:
SizeEntity -> Size
DataObjects.EntityFramework.SizeEntity -> BusinessObjects.Size

Answer 1

首先，您应该删除指定对象List的映射的初始化，您只需要定义与基础对象的映射。当您调用Map方法时，初始化会导致结果为空。

static SizeDao()
{
    Mapper.Initialize(cfg => cfg.CreateMap<SizeEntity, Size>());

    // This is not needed.
    // Mapper.Initialize(cfg => cfg.CreateMap<List<SizeEntity>, List<Size>>());
}

另外，正如@CodeCaster建议的那样，不要将映射定义放在静态构造函数中，例如，在整个应用程序的入口点，并验证在调用{{1}之前调用这些行方法。

Answer 2

因为Automapper不起作用，所以我必须执行以下操作：

 /// <summary>
        /// Gets all size from database
        /// </summary>
        /// <returns>Returns a list of Sizes</returns>
        public List<Size> GetSizes()
        {
            using (var context = new ExamContext())
            {
                var sizes = context.SizeEntities.ToList();

                //Convert SizeEntities list to Size (Business Objects) list
                var targetList = sizes
                  .Select(x => new Size() { Id = x.Id, SizeName =  x.SizeName})
                  .ToList();

                return targetList;
                //return Mapper.Map<List<SizeEntity>, List<Size>>(sizes);
            } 
        }

AutoMapperMappingException：缺少类型映射配置或不支持的映射，映射类型列表

2 个答案: