使用 Automapper 进行复杂对象映射

Question

我正在尝试使用自动映射器来实现以下代码。

List<VlaListView> vlaVmList = new List<VlaListView>();
var vlaCollectionList = vlaCollection.ToList(); //database populate list

foreach (var vla in vlaCollectionList)
{
    VlaListView vlaVm = new VlaListView();
    vlaVm.VlaId = vla.VlaId;
    vlaVm.UserName = vla.UserName;
    vlaVm.DateOut = vla.DateOut.ToShortDateString();
    vlaVm.ReturnDate = vla.ReturnDate.ToShortDateString();
    vlaVm.Status = vla.Status;

    string regnumbers = string.Empty;

    foreach (var vehicle in vla.Vehicles)
    {
        regnumbers += vehicle.RegistrationNumber + ", ";
    }

    regnumbers = regnumbers.Remove(regnumbers.Length - 2);
    vlaVm.RegistrationNumbers = regnumbers;

    vlaVmList.Add(vlaVm);
}

我得到了除了注册号之外的所有值来映射，它可以有一个带有注册号的车辆列表。我正在尝试循环并获取vla.vehicles.RegistrationNumber 的值，将结果连接起来并将其保存到我的视图模型字段中。我的 Automapper 代码如下

AutoMapper.Mapper.Initialize(config =>
{
    config.CreateMap<Vla, VlaListView>()
        .ForMember(x => x.DateOut, opt => opt.MapFrom(src => src.DateOut.ToShortDateString()))
        .ForMember(x => x.ReturnDate, opt => opt.MapFrom(src => src.ReturnDate.ToShortDateString()))

        // this is the ForMember I can't work out, I can't get the values of the registration numbers
        .ForMember(x => x.RegistrationNumbers, opt => opt.MapFrom(src => src.Vehicles.Select(v => string.Join(", ", v.RegistrationNumber))));
});

对此的任何帮助将不胜感激。

Answer 1

你很接近，但string.Join 应该在Select 之外（目前它编译只是因为string 是IEnumerable<char>，因此达到this overload，结果是一些奇怪的逗号连接的字符串列表字符）：

.ForMember(dest => dest.RegistrationNumbers, opt => opt.MapFrom(src =>
    string.Join(", ", src.Vehicles.Select(v => v.RegistrationNumber))));