Backing different prop type in .NET, EF with C#-CodePudding

I tried to do the following:

Product model:

public class Product : BaseEntity
{
    public string Name { get; set; }
    public string Description { get; set; }
    private string _PictureUrls;

    [NotMapped]
    public string[] PictureUrls
    {
        get { return _PictureUrls.Split(','); }
        set { _PictureUrls = string.Join(',', value); }
    }
}

and:

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
  modelBuilder
      .Entity<Product>()
      .Property(props => props.PictureUrls)
      .HasField("_PictureUrls")
      .UsePropertyAccessMode(PropertyAccessMode.PreferFieldDuringConstruction);
}

I keep getting the error:

The specified field '_PictureUrls' of type 'string' cannot be used for the property 'Product.PictureUrls' of type 'string[]'. Only backing fields of types that are compatible with the property type can be used.

I understand why, but can't figure out how to solve this, help please.

CodePudding user response：

Do consider making PictureUrl an entity, but what you're attempting will work.

The string needs to be a shadow property of string type, not mapped to the array property. eg

    modelBuilder.Entity<Product>()
                .Property(typeof(string), "_PictureUrls")
                .HasField("_PictureUrls")
                .HasColumnName("PictureUrls")
                .UsePropertyAccessMode(PropertyAccessMode.PreferFieldDuringConstruction);