在实体框架中复制实体？

Question

For example I have a wpf window bound to an customer Entity (let suppose it's cus1). Then I load another entity from context :

customer cus2 = context.customers.where(x=>x.id=10).FirstOrDefault();

Now I want cus1 = cus2 ? I can do this way :

cus1.name = cus2.name;
cus1.address = cus2.address;
...
...

This way meets my case (the content of textboxs in the form change immediately into values of cus2) but I wonder if there is anyway to make it shorter since cus1=cus2 doesn't work ?

Thanks

Answer 1

您可以使用memberwise Clone方法来制作业务对象的浅表副本：请参阅http://msdn.microsoft.com/de-de/library/system.object.memberwiseclone.aspx

Answer 2

If you want to update the values of a Customer entity in memory with the newest values in the datastore you can use the Refresh method on your ObjectContext.

Here is the documentation .

In your case it would look like:

context.Refresh(RefreshMode.StoreWins, cus1);

If you really want to map two entities you could have a look at AutoMapper . AutoMapper will help you by automatically mapping entities to each other with a default setup that you can tweak to your needs.

Answer 3

You could also use Serialization or Reflection, to do it on your own. However both oof the methods are slower then writing it directly.

Take a look at this article. Maybe you will find it helpful:

http://www.codeproject.com/KB/dotnet/CloningLINQ2Entities.aspx

Edit: Btw. Remember, using using MemberwiseClone, in case of ReferenceTypes will effect in copying the references, not objects.