Save a fetched entity in different context

I fetched an entity using a context. Then I made some changes to the entity an开发者_如何学Cd now I'd like to save the entity using a different context. I use the AttachTo method but I'm getting this error.

An entity object cannot be referenced by multiple instances of IEntityChangeTracker.

You must Detach before you can AttachTo.

That said, your life will be much simpler if you use only one context.