How to use AfterMap to map properties on collection property

This should work -

 AutoMapper.Mapper.CreateMap<Foo, FooDto>()
            .AfterMap((src, dest) =>
            {
                dest.Total = 8;//service call here
                for (var i = 0; i < dest.Bars.Count; i++)
                {
                    dest.Bars.ElementAt(i).Total = 9;//service call with src.Bars.ElementAt(i)
                }
            });
AutoMapper.Mapper.CreateMap<Bar, BarDto>();
var t = AutoMapper.Mapper.Map<FooDto>(new Foo
        {
            Bars = new List<Bar> { new Bar { } }
        });