getObjectContext的问题，急！[在线等待中...]

为什么我使用getObjectContext后程序始终告诉我为Nothing,以至于不能使用.setcomplete和.setabout。一使用就告诉我对象未定义。

源码如下：

Public Function test123() As Integer
On Error GoTo err_handle
Dim objContext As COMSVCSLib.ObjectContext
Set objContext = GetObjectContext

aaa = 3

test123 = aaa

Err.Raise (1)

objContext.SetComplete
Set objContext = Nothing

Exit Function
err_handle:
objContext.SetAbort
Set objContext = Nothing
test123 = aaa
End Function