后期绑定编译错误：未定义引用Excel VBA中的Outlook mailitem的用户定义类型

Question

I am using late binding from Excel.

I get

Compiler Error: User defined type not defined

for:

If TypeOf olMail Is MailItem Then

I declare the following variables:

Dim olApp As Object
Dim olNs As Object
Dim Fldr As Object
Dim olItms As Object
Dim olMail As Object

Set olApp = CreateObject("Outlook.Application")
Set olNs = olApp.GetNamespace("MAPI")
Set Fldr = olNs.GetDefaultFolder(olFolderInbox)
Set olItms = Fldr.Items

The code was working but I had to change to late binding because a user is not using the same Outlook version.

Answer 1

I'm guessing the reason you get the error is because you no longer have a reference to the outlook object library, and thus MailItem is an unknown type.

Instead of using TypeOf

If TypeOf olMail Is MailItem Then

use the TypeName function to compare the object type name to a string...

If TypeName(olMail) = "MailItem" Then

(note I'm assuming the type name will be MailItem , but you can always throw in MsgBox TypeName(olMail) just to be sure!)

Answer 2

Type Name function is somewhat expensive. Class property (implemented by all OOM objects) would be a better aalternative. Check that oMail.Class = 43 (43 is OlObjectClass.olMail constant)