C＃实体框架延迟加载未加载

Question

I've done all the readings I can find on Entity and lazy loading, as well as other questions here, but for the life of me I can't get this working. Here's my SQL for the DB:

CREATE TABLE corporations(
corporationID bigint PRIMARY KEY
);

CREATE TABLE Character(
personID bigint PRIMARY KEY,
corporationID int NOT NULL,
FOREIGN KEY (corporationID) REFERENCES corporations(corporationID)
);

And the Entity code to get it ( * EDITED from original, still broken * ):

DBEntities context = new DBEntities();
public Character Character_GetByID(long CharacterID)
        {
            context.ContextOptions.LazyLoadingEnabled = true;
            Character character = context.Characters.Where(c => c.CharacterID == CharacterID).FirstOrDefault();      
            return character;
        }

So from my understanding, with this I should be able to go

Character char = Character_GetByID(characterID);
Corporation corp = char.Corporation;

The "char.Corporation" object exists, Entity created it properly from the foreign key. But when I run the above code, "corp" always returns as NULL (even though I know for sure that the relevant corporation is in the DB).

One thing I did notice is that in the auto-generated Entity Character object, it has the function:

public virtual Corporation Corporation
        {
            get { return _corporation; }
            set
            {
                if (!ReferenceEquals(_corporation, value))
                {
                    var previousValue = _corporation;
                    _corporation = value;
                    FixupCorporation(previousValue);
                }
            }
        }

Which seems odd, because I would assume that with lazy loading the "get" function would be something like "if null, try to get Corporation from database". Any thoughts would be highly appreciated.

* EDIT * Request for how lazy loading is configured:

In my Context class, for every constructor I have

this.ContextOptions.LazyLoadingEnabled = true;

And as you can see from the first C# function up above, I tried setting it as true in the function itself, just before querying it.

Answer 1

Lazy loading is a functional provided by object context (DBEntities class instance in your case). So, it will work only when entity object is attached to some DBEntities instance. When Character_GetByID method is done, context is disposed, entity is detached, and your lazy loading request cannot be performed.

Answer 2

Remove the using statement, as when you use this dbcontext is disposed right away

using (var context = new DBEntities())
{
   ...
}//context is disposed here... lazy loading is not possible

Answer 3

use a .Include(x=> x.Corporation) ;

For some info on loading related data.

http://www.asp.net/mvc/tutorials/getting-started-with-ef-using-mvc/reading-related-data-with-the-entity-framework-in-an-asp-net-mvc-application