C# Outlook Late Binding add Attachment

Posted on 2010-08-20
Last Modified: 2012-05-10
How do I add an attachment to e-mail using assembly reflection in C#?
In other words, how do I translate:
Microsoft.Office.Interop.Outlook.Attachment oAttach = oMsg.Attachments.Add(sSource,1, 1, "");?
The following code throws error on the attachments step.
Everything else works.
           oApp = Activator.CreateInstance(outlook);
            object mailItem = oApp.GetType().InvokeMember("CreateItem", BindingFlags.InvokeMethod, null, oApp, new object[] { 0 });
            mailItem.GetType().InvokeMember("Subject", BindingFlags.SetProperty, null,mailItem, new string[] {"Report"});
            Object attachments = mailItem.GetType().GetProperty("Attachment",BindingFlags.GetProperty);
            attachments.GetType().InvokeMember("Add", BindingFlags.InvokeMethod, null, attachments, new object[] { att,1,1,"CrystalReport1.rpt.pdf" });
            mailItem.GetType().InvokeMember("Display", BindingFlags.InvokeMethod, null, mailItem, new object[] { true });
Question by:josephdts
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Expert Comment

by:Éric Moreau
ID: 33487212
I know it is not exactly what you are asking for but have a look at

Author Comment

ID: 33487258
Does not work for me. I would like to open Outlook with the attachment without sending it.
It seems to be easy to do it in VB.NET that is not strongly typed, but I need it on C#, and I cannot find any code on line. All my aatempts so far have failed. I got as far as getting the Attachment Object:
Object attachment = mailItem.GetType().GetProperty("Attachment", BindingFlags.SetProperty);
LVL 69

Expert Comment

by:Éric Moreau
ID: 33487756
>> I would like to open Outlook with the attachment without sending it.

this is exactly waht it is doing
>> but I need it on C#,
The downloadable demo contains a C# version!

Author Comment

ID: 33487913
Very Interesting! I am also develping a button for the Crystal Viewer that generates e-mail with PDF attachment. I cannot find the downloadable demo  link. The code that I see uses MAPI, not Outlook.
It is more secure, but less friendly.
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LVL 69

Accepted Solution

Éric Moreau earned 125 total points
ID: 33487947

Author Comment

ID: 33488855
I have visual studio 2008. I have copied the namespace, and when I try to compile it complains that
Type or Namespace DLLImport could not be found. I cannot find it in the References either. I see it in \\Windows\System32. How do I add it as Reference? What about 64 bit?

Author Comment

ID: 33489038
Works in my test Application! Many thanks!

Author Closing Comment

ID: 33489044
Will it work in 64 bit environment?
LVL 69

Expert Comment

by:Éric Moreau
ID: 33490090
>>Will it work in 64 bit environment?
I am on a 64-bits OS and it is working.

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