Available events and their dispids (Outlook exported APIs)
This section describes the dispatch identifiers for the events that Outlook makes available.
Outlook exposes the following dispatch identifiers (dispids) to allow C++ add-ins to listen to and handle the corresponding events from the IDispatch::Invoke function.
| Constant | Dispid for event | Description | Parameters | Remarks |
|---|---|---|---|---|
| dispidBeforePrint | 0xFC8E | Used to handle the application-level event from the IDispatch::Invoke function that fires before a printing operation. | There are 2 unnamed parameters: The first parameter is of the type VT_BOOL|VT_BREF. Return VARIANT_TRUE in this parameter to cancel the event. The second parameter is not used and should be ignored. | This dispid is available since Outlook 2010. |
| dispidEventReadComplete | 0xFC8F | Used to handle the item-level event from the IDispatch::Invoke function that fires when Outlook has completed reading the properties of the item. | There is only one parameter Cancel which is of the type VT_BOOL|VT_BREF. Return VARIANT_TRUE in this parameter to cancel the read operation. | This dispid is available since Outlook 2010. This event corresponds to the Exchange Client Extensions (ECE) event IExchExtMessageEvents::OnReadComplete, and also to the ReadComplete event that has been added to the object model since Outlook 2013. |
For an example of how to use a dispid to listen to and handle an event, see the CAppEventListener::Invoke function in the C++ Outlook solution described in Implementing Outlook 2002/XP Event Sinks in MFC C++ 2003 .NET.