How to ignore properties based on their type

Question

I'm using AutoMapper to copy an entity framework object to another identical database. The problem is that it tries to copy the lookup tables.

I have tried to exclude them with the AddGlobalIgnore and the ShouldMapProperty but it doesn't work. AutoMapper still try to copy those properties.

Here's my code. I would like to ignore the properties that start with "LU"

 dynamic newObject= new NewObject();

 MapperConfiguration config = new MapperConfiguration(cfg =>
 {
     cfg.CreateMissingTypeMaps = true;
     cfg.AddGlobalIgnore("LU");
     cfg.ShouldMapProperty = p => !p.GetType().ToString().StartsWith("LU");
     cfg.ShouldMapField = p => !p.GetType().ToString().StartsWith("LU");
 });
 IMapper mapper = config.CreateMapper();
 newObject = mapper.Map(objectToCopy, objectToCopy.GetType(), newObject.GetType()); 

I did also tried

MapperConfiguration config = new MapperConfiguration(cfg =>
{
   cfg.CreateMissingTypeMaps = true;
   cfg.AddGlobalIgnore("LU");
   cfg.ShouldMapProperty = p => !p.PropertyType.Name.StartsWith("LU");
   cfg.ShouldMapField = p => !p.FieldType.Name.StartsWith("LU");
 });

and

MapperConfiguration config = new MapperConfiguration(cfg =>
{
   cfg.CreateMissingTypeMaps = true;
   cfg.AddGlobalIgnore("LU");
   cfg.ShouldMapProperty = p => !p.Name.StartsWith("LU");
   cfg.ShouldMapField = p => !p.Name.StartsWith("LU");
});

Answer 1

Create your configuration as a separate profile, then add that profile to the mapper configuration.

class Program
{
    static void Main(string[] args)
    {
        dynamic newObject = new NewObject();
        var objectToCopy = new ObjectToCopy();

        var config = new MapperConfiguration(cfg =>
        {
            cfg.AddProfile<MyProfile>();
        });

        var mapper = config.CreateMapper();
        mapper.Map(objectToCopy, newObject);
        // newObject.LU_Ignore = "Original value"
        // newObject.DoNotIgnore = "New value"
    }
}

class MyProfile : Profile
{
    protected override void Configure()
    {
        CreateMissingTypeMaps = true;
        ShouldMapProperty = p => !p.Name.StartsWith("LU"); // this is the correct way to get the property name
    }
}

class ObjectToCopy
{
    public string LU_Ignore { get; set; } = "New value";

    public string DoNotIgnore { get; set; } = "New value";
}


class NewObject
{
    public string LU_Ignore { get; set; } = "Original value";

    public string DoNotIgnore { get; set; } = "Original value";
}

Something seems goofy about how configurations are applied to the Mapper created form the mapper.CreateMapper call. I'm looking into it to see if I can find out more information and will update this answer if I find anything.