Dual Interfaces

Use COM interfaces to access the properties and methods on any provider ADSI objects. A read-only property maps to an interface entry of the form get_<PropertyName>. A read/write property maps to two interface entries of the form get_<PropertyName> and put_<PropertyName>.

All methods on a COM interface must:

• Return an HRESULT value to indicate success or failure. The HRESULT type is discussed in the COM specification.
• Return E_NOTIMPL for interfaces that have not been implemented.
• Return E_ADS_PROPERTY_NOT_SUPPORTED for interface properties that are not supported.

To retain compatibility with Automation controllers, all parameters and return types should be within the subset defined by the Automation VARIANT data type. For more information, see VARIANT and VARIANTARGS in the Microsoft Platform SDK.

A provider Active Directory object can expose interfaces that use data types other than those in the VARIANT subset. However, Automation controllers such as Visual Basic will not be able to call those interfaces. Since all ADSI provider interfaces are derived from IDispatch, they can be used as IDispatch interface pointers.