Context Tracking

[Oliver Cox]

Hi,

I downloaded the Silberlight Data Services example and begun to put together my own example but have encountered two issues:

1. When editing a record the error below is thrown when calling context.AddToEntities(entity) method.
    "The context is already tracking the entity."
2. When adding a new entity and moving from one cell to the next the error below is thrown when calling UpdateObject(entity)
    "The context is not currently tracking the entity."

Now presumably I am doing someting wrong here or not accounting for some difference in the versions used in the example. Howver, my real question is how do I test if an entity is already added to the context? Is there for instance any way of testing for context.Entities.Conatins(entity)?

Any help would be greatly appreciated.

Thanks

Oliver

[PetarP]

Hi Oliver Cox,

You can use the TryGetEntity. If that method does not return anything then the entity is not being tracked and needs to be added. If however the method returns an entity then you will have call the update method rather than add it again since the entity is already being tracked by the context.

Best wishes,
Petar
the Telerik team

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[Iky]

Hi, i can't seem to find any documentation on the TryGetEntity method and I'm not too sure how i would use it. The entity I'm trying to update has a composite key.    

Could you show me a basic usage example or direct me to Documentation?

Thanks

[Ady]

Hello Iky,

The method is called 'TryGetObjectByKey'.
If you tell me what you want to achieve maybe I could provide a more specific solution to your problem.

Regards,
Ady
Telerik