Creating an Extension Method to Support Late Binding

Adding support for late binding tools, such as VBScript, JScript, and so on, requires more work than adding an early binding extension. You must add support for the IADsExtension interface and delegate IDispatch in the same way that IUnknown is delegated for early binding. At the time of this writing, the Active Template Library (ATL) didn't provide support for delegating internal IDispatch activity, so you will probably need to provide this functionality.

Note   If you are creating a new extension you will need to review Creating an Extension Method to Support Early Binding. This may not be necessary if you need only to add late binding support to an existing extension.

If your extension supports late binding, it can be accessed by using late binding Automation clients, such as Windows Script Host, Active Server Pages, and VBScript, as well as by early binding tools such as Visual Basic and Visual C++.

The following is an example of late binding code for accessing your extension:

Set MyObj = GetObject("IIS://LM/W3SVC")
Debug.Print MyObj.LastBackup
MyObj.Backup

This topic contains:

• The IADsExtension Interface: Introduction to the IADsExtension interface and its methods.
• Rerouting the Internal IDispatch: Shows how to reroute IDispatch calls through the object manager of the IADsExtension interface.
• Adding an IADsExtension Interface Implementation: Explains how to add support for the ADs defined IADsExtension interface.

For more information regarding the IADs and IADsExtension interfaces, see the ADSI Reference section, under the Networking Services topic, in the Platform SDK.