如何使用自动映射器将多对多映射

Question

I have many to many relation for tables functions and roles and I have association table RolesFunctions. In the RolesFunctions I have row id ( IdFunctions and IdRoles Both its a prime key). the problem is when I map function with functionDTO and roles with rolesDTO with AutoMapper I have this error "An unhandled exception of type 'System.StackOverflowException' occurred in AutoMapper.dll. Make sure you do not have an infinite loop or infinite recursion."

my mapping :

CreateMap<Function, FunctionTDTO>().ReverseMap();
CreateMap<Roles, RolesDTO>().ReverseMap();

How automapper map many to many relationship ?

function classe

public class Functions
    {
        public Functions()
        {
            this.Roles = new HashSet<Roles>();
        }
        public int Id { get; set; }
        public string Description { get; set; }
        public virtual ICollection<Roles> Roles { get; set; }
    }

function DTO

public class FunctionsDTO
    {
        public int Id { get; set; }
        public string Description { get; set; }
        public virtual ICollection<RolesDTO> Roles { get; set; }
    }

Role classe

public class Roles
    {
        public Roles()
        {
            this.Functions = new HashSet<Functions>();
        }
        public int Id { get; set; }
        public string Libelle { get; set; }
        public virtual ICollection<Functions> Functions { get; set; }
    }

RoleDTO classe

public class RolesDTO
    {
        public int Id { get; set; }
        public string Libelle { get; set; }
        public virtual ICollection<FunctionsDTO> Functions { get; set; }
    }

Answer 1

It is not a good practice to have reference in one DTO to second DTO because it cause many troubles (this, for example). You should make your DTOs based on your use case. For example in:

public class FunctionsDTO
{
    public int Id { get; set; }
    public string Description { get; set; }
    public virtual ICollection<RolesDTO> Roles { get; set; }
}

When you only need to use Roles.Libelle (for example in displaying or creating), you should make for example this DTO:

public class FunctionsCreateDTO
{
    public int Id { get; set; }
    public string Description { get; set; }
    public virtual ICollection<string> RoleLibelles { get; set; }
}

And then just change your Mapping.