Automapper upgrade woes...does not exist in the type

Question

I recently did a pretty big upgrade from a much older version of Automapper to the latest.

The upgrade caused a lot of headaches, but the Automapper upgrade guide helped a lot ( https://docs.automapper.org/en/stable/8.0-Upgrade-Guide.html ).

One of the last issues I am dealing with is this:

I changed this:

cfg.CreateMap<String, String>()
    .ConvertUsing(Conversion.TrimToNull);
    

To this:

cfg.CreateMap<String, String>()
    .ConvertUsing(new Conversion.TrimToNull);

Using a class called Conversion that looks like this:

public static class Conversion
{
    public static String TrimToNull(this String str)
    {
        return str?.Trim().Coalesce(null);
    }
}

But now I am getting this error:

The name 'TrimToNull' does not exist in the type Conversion

I am not sure why it doesn't see TrimToNull even though it's in the class.

What could I be doing wrong. It worked in the older version of Automapper.

Thanks!

Answer 1

Looking at the auto-mapper guide it seems that they changed the signature from Func<> to Expression<Func<>>. Auto Mapper Convert Using Update

I believe for that reason you want:

cfg.CreateMap<String, String>().ConvertUsing(x => Conversion.TrimToNull(x));