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.

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You must Detach before you can AttachTo.

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