Convert POCO object to Proxy object in EntityFrame

问题:

I have a MVC3 Project and I have run into a problem. I have a Create controller which takes as a parameter one of my POCO objects. I add this object to the database like this:

  entity = dbSet.Add(entity);

After this method returns, I would like to use the lazy loading features of the object. Unfortunately the object is not a Proxy object generated by the EntityFramework...Is there a way to somehow solve this?

Thank You, AFrieze

回答1:

The entity must be already proxied when you pass it to Add method. Add method will not return another instance of the class and you cannot change the type of the existing instance to the proxy type.

Your options are:

• Not using entity as input in controller - use some view model and populate new entity created by dbSet.Create - this will create empty proxied detached entity.
• Instead of adding the entity received in controller create a new one by dbSet.Create and copy data from received one to created one
• Don't use default model binder. Create custom model binder (that is the code responsible for extracting data from HTTP request and populating parameters passed to controller) which will use dbSet.Create instead of default entity constructor.