You write an event procedure (also known as an event handler) to respond to events that occur in Microsoft Outlook. For example, you can write an event procedure that automatically maximizes the explorer window when Outlook starts.
Events are associated with particular objects. The Application object is the topmost object, and is always available (that is, it does not have to be created). You can add an Application event procedure in the ThisOutlookSession module window simply by selecting Application in the left list and then selecting the event in the right list.
Adding an event handler for objects other than the Application object requires a couple of more steps.
First, you must declare a variable using the WithEvents keyword to identify the object whose event you want to handle. For example, to declare a variable representing the OutlookBarPane object, you would add the following to a code module.
Dim WithEvents myOlBar as Outlook.OutlookBarPane
You can then select myOlBar in the left list of the module window and then select the event in the right list. The Visual Basic Editor will then add the template for the event procedure to the module window. You can then type the code you want to run when the event occurs. The following example shows code added to the BeforeNavigate event procedure for the OutlookBarPane object.
Private Sub myOlBar_BeforeNavigate(ByVal Shortcut As OutlookBarShortcut, Cancel As Boolean)
If Shortcut.Name = "Notes" Then
MsgBox "You cannot open the Notes folder."
Cancel = True
End If
End Sub
The final step is to add code to set the object variable to the object whose event you want to handle. This code can exist in a macro, or if you want the event to be handled whenever Outlook runs, you can put it in the Startup event procedure, as in the following example.
Private Sub Application_Startup()
Set myOlBar = Application.ActiveExplorer.Panes(1)
End Sub