我有一个父类:
public class Parent
{
...
public List<Location> Locations { get; set; }
}
位置等级:
public class Location
{
public int LocationId { get; set; }
public string Name { get; set; }
}
映射的目标类:
public class Destination
{
...
public string DelimitedLocations { get; set; }
}
我需要使用automapper将LocationId列表从Locations映射到逗号分隔的字符串。
以下是我尝试过的几件事:
CreateMap<Parent, Destination>().ForMember(d => d.DelimitedLocations , o => o.MapFrom(s => string.Join(",", s.Locations.ToList().Select(t => t.LocationID.ToString()))))
结果: LINQ to Entities无法识别方法&#39; System.String Join(System.String,System.Collections.Generic.IEnumerable`1 [System.String])&#39;方法,并且此方法无法转换为商店表达式。
下一次尝试:
CreateMap<Parent, Destination>()..ForMember(d => d.TestPlotLocationsSelected, o => o.MapFrom(s => s.TestPlotLocations.ToList().Select(t => string.Join(",", t.TestPlotLocationID.ToString()))))
结果: 没有方法&#39; ToString&#39;存在于&#39; System.Collections.Generic.IEnumerable`1 [System.String]&#39;中。
不确定接下来要尝试什么。
答案 0 :(得分:1)
Select语句应该类似于
o.Locations.Select(x => x.LocationId).ToList()
public class Program
{
public static void Main()
{
Initialize();
var source = new Parent
{
Locations = new List<Location>
{
new Location {LocationId = 1, Name = "One"},
new Location {LocationId = 2, Name = "Two"},
new Location {LocationId = 3, Name = "Three"},
}
};
var destination = Mapper.Map<Parent, Destination>(source);
Console.ReadLine();
}
public static void Initialize()
{
MapperConfiguration = new MapperConfiguration(cfg =>
{
cfg.CreateMap<Parent, Destination>()
.ForMember(dest => dest.DelimitedLocations, mo => mo.MapFrom(src =>
src.Locations != null
? string.Join(",", src.Locations.Select(x => x.LocationId).ToList())
: ""));
});
Mapper = MapperConfiguration.CreateMapper();
}
public static IMapper Mapper { get; private set; }
public static MapperConfiguration MapperConfiguration { get; private set; }
}
public class Parent
{
public List<Location> Locations { get; set; }
}
public class Location
{
public int LocationId { get; set; }
public string Name { get; set; }
}
public class Destination
{
public string DelimitedLocations { get; set; }
}