When using AutoMapper, it may be that we’re using types which map easily to one another, for example if the objects being mapped have the same type for a property or the type can be converted using the standard type convertes, but what happens when things get a little more complex?

Suppose we have a type, such as

public class NameType
{
   public string Name { get; set;
}

and we want to map between a string and the NameType, for example

var nameType = Mapper.Map<string, NameType>("Hello World");

As you might have suspected, this will fail as AutoMapper has no way of understanding how to convert between a string and a NameType.

You’ll see an error like this

Missing type map configuration or unsupported mapping.

Source value:
Hello World

What we need to do is give AutoMapper a helping hand. One way is to supply a Func to handle the conversion, such as

Mapper.CreateMap<string, NameType>().
	ConvertUsing(v => new NameType { Name = v });

alternatively we can supply an ITypeConvert implementation, such as

public class NameConverter :
   ITypeConverter<string, NameType>
{
   public NameType Convert(ResolutionContext context)
   {
      return new NameType {Name = (string) context.SourceValue};
   }
}

and use in like this

Mapper.CreateMap<string, NameType>().
   ConvertUsing(new NameConverter());