Entity Framework CTP4 Code First: Mapping protected properties

问题

I would like to use a lazy-loading collection on a model, but I want Add/Remove functionality to be done through separate methods. So something like this:

class Model
{
  protected virtual ICollection<Something> _somethings { get; set; }

  public IEnumerable<Something> Somethings 
  { 
    get { return _somethings; } 
  }

  public void AddSomething(Something thingToAdd)
  {
    /*  logic */
    _somethings.Add(thingToAdd);
  }
}

I can't figure out how to configure the mapping for this. I looked into using a configuration class: EntityConfiguration. But since the property is protected I can't figure out how to set a configuration on it. Is there any way to accomplish what I'm trying to do here?

回答1:

You can use readonly static Expression for access to protected property like this

protected virtual ICollection<Something> _somesing { get; set; }
public static readonly Expression<Func<Model, ICollection<Something>>> Expression = p => p._something;

public IReadOnlyCollection<Something> Something
{
     return _sumething.AsReadOnly();
}

And use it in OnModelCreating method in DbContext class for mapping protected property

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder.Entity<Model>().HasMany<Something>(Model.Expression);
}

回答2:

I suppose if you declare the configuration class (inheriting EntityConfiguration) inside your Model class, it could work. It's not a nice solution, since subclassing is generally discouraged, but it's the only thing I can think of.

回答3:

Ive heard this only can be done using EDMX file way.. not code first.

来源：https://stackoverflow.com/questions/3577891/entity-framework-ctp4-code-first-mapping-protected-properties

标签

entity-framework-4

code-first