自动映射器子映射与中间的实体

Question

我有以下要映射到Dto的实体结构

上下文实体

public class CallPoint
{
    public int Id { get; set; }
    public string Name {get; set;}
    public ICollection {UserCallPoint} UserCallPoints {get; set;}
}

public class UserCallPoint
{
    public int Id {get; set;}
    public CallPoint CallPoint {get; set;}
    public User User {get; set;
}

public class User
{
    public int Id {get; set;}
    public string Email {get; set;}
    public ICollection<UserCallPoint> UserCallPoints {get; set;
}

DTO

public class CallPointDto
{
    public int Id { get; set; }
    public string Name { get; set; }
    public List<UserDto> Users { get; set; }
}

public class UserDto
{
    public int Id { get; set; }
    public string Email { get; set; }
    public List<CallPointDto> CallPoints { get; set; }
}

所以基本上我有很多对很多的映射，但是它们之间确实有一个实体，基本上充当查找表。 我该如何映射？ 我目前只是像下面这样循环和映射，但是它太慢了

    private List<CallPointDto> MapCallPoint(List<CallPoint> callPoints)
    {
        List<CallPointDto> callPointDtos = new List<CallPointDto>();
        foreach (var callPoint in callPoints)
        {
            var callPointDto = _mapper.Map<CallPointDto>(callPoint);
            callPointDto.Users = new List<UserDto>();
            foreach (var item in callPoint.UserCallPoints)
            {
                UserDto userDto = _mapper.Map<UserDto>(item.User);
                callPointDto.Users.Add(userDto);
            }
            callPointDtos.Add(callPointDto);
        }
        return callPointDtos;
    }

如何使用自定义解析器执行此操作？

Answer 1

由于n：m关系可能会无限运行，因此我无法为您提供所需的答案。 但我建议您像这样使用不同的子DTO：

public class CallPointBaseDto
{
    public int Id { get; set; }
    public string Name { get; set; }
}
public class CallPointDto : CallPointBaseDto
{
    public List<UserBaseDto> Users { get; set; }
}

public class UserBaseDto
{
    public int Id { get; set; }
    public string Email { get; set; }
}
public class UserDto : UserBaseDto
{
    public List<CallPointBaseDto> CallPoints { get; set; }
}

对应：

cfg.CreateMap<CallPoint, CallPointDto>()
    .ForMember(dest => dest.Users, opt => opt.MapFrom(src => src.UserCallPoints.Select(ucp => ucp.User)));
cfg.CreateMap<User, UserBaseDto>();

当然，这样做的缺点是，UserBaseDto中没有CallPoints，但是如果需要，可以显式调用此User并以其他方式映射它。