Item Enumeration

Outlook (probably for backward compatibility reasons) doesn’t have a default Outlook.Item object as the parent of the various Outlook.Items (Outlook.MailItem, PostItem, AppointmentItem). This means code like this wouldn’t work:

dim oItem as Outlook.MailItem
for each oItem in Outlook.ActiveExplorer.Selection
' you get errors for any items (like PostItem), that isn't an 
MailItem in your inbox
MsgBox oItem.Subject
next

Figure: Example of incorrect code

So you have to write something like this:

dim oItem as Object
for each oItem in Outlook.ActiveExplorer.Selection
' this will work, because every type of Outlook Item has the subject property... 
' but we're relying on reflection (late binding) here and 
' intellisense doesn't help us when we write code,
' compiler doesn't tell us if we made a typo,
' late binding is slower...
MsgBox oItem.Subject
next

Figure: Example of correct code

The current object model does not make for nice and easy plugin development. Some issues include:

Setting the title of the COM addin in the options page:

To set the title using VSTO you have to have code like this, which is rather unnatural:

[System.Runtime.InteropServices.DispId(-518)]
public string Caption 
{
	get {return "SSW eXtreme Emails";}
}

Throw out backwards compatibility and start a fresh. For example, you should be able to inherit the contacts page and change the way it looks and add extra functionality to it.

I want to know who created this contact and who updated the information for this contact, it should have “Created By” and “Updated By” fields.

Suggestion: Adding “Created By” and “Updated By” fields for contact information, and automatic save the logon user to the fields after a contact information was created or updated.

We have a rule better to interfaces about this, please see Data Entry Forms – The way to develop Data Entry Forms – Created/Last Updated By Fields