Automapper: CreateMap but for a property which is not initialized yet - automapper

Question

How can I create a Map with Automapper when in the underlying destination type a property not yet has initialized?
Example:
public class UserAccount
{
public string name { get; set; }
public Dictionary<string,string> properties { get; set; }
}
public class UserAccountOtherType
{
public string name { get; set; }
public string Property1 {get;set; }
}
public static UserAccount CustomMap(UserAccountOtherType type2)
{
AutoMapper.Mapper.CreateMap<UserAccount,UserAccountOtherType>()
.ForMember(dest => dest.properties["Property1", opt => opt.MapFrom(src => (string)src.Property1));
return AutoMapper.Mapper.Map<UserAccount,UserAccountOtherType>(type2);
}
When I try to execute this code it fails because the Dictionary in UserAccount is not yet initialized. I cannot initialize the Object by myself because the UserAccount Class is a Datacontract of a WCF Serviceinterface.
I have to create a Dicationary by myself and assign it to the property.
UserAccount b = new UserAccount();
Dictionary<string,string> properties = new Dictionary<string,string>();
b.properties = properties;
How can I solve this with Automapper? Or is my approach not senseful?

Answer 1

Only way I can think of to do something like this is to write a class that implements AutoMapper.IValueResolver. Then opt.MapFrom... becomes opt.ResolveUsing....FromMember... Probably at that point your destination is the entire dictionary (I think if you leave out the FromMember you get the whole object into your resolver
in your implementation of IValueResolver.Resolve, try breaking into the debugger and checking out the ResolutionContext in source.Context, then once you have your dictionary built, return source.New(myDictionary)