Resolution of Multiple Aggregation Components Supporting the Same Interface

It is uncommon that two extensions expose the same interface to ADSI. If this happens, the following rules apply:

  • If an interface, such as IMyInterface, is supported by both the aggregator (ADSI) and any extension objects, QueryInterface always returns the IMyInterface for ADSI.
  • If an interface, such as IMyInterface, is not supported by the aggregator (ADSI), but is supported by more than one extension object, QueryInterface returns the IMyInterface of the first extension object listed in the registry that supports the interface.

Be aware that the order of components in the registry also affects the resolution of name conflicts in Automation. For more information, see Resolution of Function/Property Name Conflicts in Automation in Extensions.