For retrieveMultiple:
EntityCollection entities = (EntityCollection)context.OutputParameters["BusinessEntityCollection"];
For retrieve:
Entity entity = (Entity)context.OutputParameters["BusinessEntity"];
The cool thing about retrieve multiple is that any adjustments that you make in retrieve will be applied for retrieve multiple.
After adjustments have been made then it's just a matter of issuing the following:
- xrm.Attach(phoneNumber);
- xrm.UpdateObject(phoneNumber);