即使在 Outlook 中，如何附加到 BeforeAttachmentRead？

Question

I'd like to take some action before users view attachments in Outlook and would like to hook into the BeforeAttachmentRead event in a VSTO plugin. I've seen code that iterates through the inbox and adds the event to each MailItem :

foreach (object o in inbox.Items)
{
 mailItem = o as Outlook.MailItem;
 ...
 ((Outlook.ItemEvents_10_Event)mailItem).BeforeAttachmentRead += new Outlook.ItemEvents_10_BeforeAttachmentReadEventHandler(MailItem_BeforeAttachmentRead);
}

But this seems very inefficient to me (and what about subfolders in the inbox?)

Is there a more efficient way to respond to the BeforeAttachmentRead event?

Answer 1

But this seems very inefficient to me (and what about subfolders in the inbox?)

I agree it would be.

I would suggest you subscribe to the selection change event of the Outlook Explorer . Now everytime the user selects something you can check if it is a mailitem (it can be other things) and then subscribe to the BeforeAttachmentRead event. You could actually check for MailItem Attachments count first. . If the mail item does not have attachments then you have nothing to do.

A few other things to check;

1. Check that Explorer CurrentFolder.WebViewOn is false;
2. Check the selection count - you only want to do something if it is 1
3. A user can select many different things. Before you cast your selection check it actually is of type Outlook.MailItem