Question

你好，我已经写了一个通用方法将DTO映射到POCO，反之亦然。但是，当我传递POCO列表时，它不会将其映射到DTO列表。看下面：

public static class BaseMapper<T, TD>
    where T : class
    where TD : class
{
    public static List<TD> Map(List<T> entity)
    {
        var config = new MapperConfiguration(cfg => cfg.CreateMap<List<T>, List<TD>>());
        var mapper = config.CreateMapper();
        return mapper.Map<List<TD>>(entity);
    }

    public static List<T> Map(List<TD> dto)
    {
        var config = new MapperConfiguration(cfg => cfg.CreateMap<List<TD>, List<T>>());
        var mapper = config.CreateMapper();
        return mapper.Map<List<T>>(dto);
    }

}

这是我的POCO：

public partial class Company : Core
{
    public string Title { get; set; }
}

/// <summary>
/// Company Virtual Properties
/// </summary>
public partial class Company
{
    public virtual ICollection<Cartable> Cartables { get; } = new HashSet<Cartable>(); 
}

这是我的DTO

public class CompanyDTO : CoreDTO
{
    public string Title { get; set; }
}

此方法返回具有记录的List<Company>，然后我使用map获取一个List<CompanyDTO>，然后为其空。

using static BaseMapper<Company, CompanyDTO>;
public Response<List<CompanyDTO>> GetAll(Guid currentUserId, int pageNum, int pageSize)
{
    var ProcessResponse = new Response<List<CompanyDTO>>();
    try
    {
        var entities = _unitOfWork.Companies.Query().OrderBy(x => x.Title).Skip(pageNum * pageSize).Take(pageSize).ToList();
        ProcessResponse.Result = Map(entities); //it turns out null here. 
        ProcessResponse.RecCount = _unitOfWork.Companies.Query().Count();
    }
    catch (Exception ex)
    {
        ProcessResponse.Failed(ex.Message, ex.InnerException.Message);
    }
    return ProcessResponse;
}

Answer 1

您需要为实体类型而不是集合类型进行映射。即

new MapperConfiguration(cfg => cfg.CreateMap<TD, T>());

代替

new MapperConfiguration(cfg => cfg.CreateMap<List<TD>, List<T>>());

然后它将起作用。

P.S。 Automapper的文档非常好-您没有尝试阅读吗？ https://docs.automapper.org/en/stable/Lists-and-arrays.html

Automapper不会将T的通用集合映射到TD的通用集合

1 个答案: