Problem auto mapping => collection of view models

Question

I have something like this

public class AViewModel
{
    public decimal number { get; set; }
    public List<BViewModel> BVM { get; set; }
}

public class BViewModel
{
    public string someString{ get; set; }
}

public class SomeObject
{
    public decimal number { get; set; }
    public List<OtherObjects> BVM { get; set; }
}

public class OtherObjects {
    public string someString{ get; set; }
}

Mapper.CreateMap<SomeObject,AViewModel>();

When I have this I get

• Trying to map OtherObjects to BViewModel
• Using mapping configuration for SomeObject to AViewModel
• Destination property: BVM
• Missing type map configuration or unsupported mapping.
• Exception of type 'AutoMapper.AutoMapperMappingException' was thrown.

How can I help it figure out how to map it properly?

Answer 1

I believe Automapper needs to know how to convert OtherObject to BViewModel. Try adding a mapping for that too.

Answer 2

You need to specify a typeconverter between OtherObject and BViewModel by specifying a custom type converter

Here's what the converter would look like:

public class OtherToBViewTypeConverter : ITypeConverter<OtherObjects, BViewModel>
{
  public BViewModel Convert(ResolutionContext context) 
  {
    if (context.IsSourceValueNull) return null;

    var otherObjects = context.SourceValue as OtherObjects;

    return new BViewModel { someString = otherObjects.someString; }
  }
}

And then the map would be called like this:

Mapper.CreateMap<SomeObject,AViewModel>().ConvertUsing<OtherToBViewTypeConverter>();