OLE and BYREF return parameters

Keywords:   BYREF return parameters

---

Question:

I have written a COM component in VB to send emails. One parameter, an error description, should be returning a value when an error is encountered. In my VB program, that parameter is defined as "ByRef". I believe that my program is working correctly, but the value that I'm passing back in ErrDescr is not showing up in my Winbatch variable. Any ideas?

MailObj = ObjectOpen("dllSendMail.dllSendMail")
Sender = "crccdi@exchange.nordstrom.com"
Recipient = "xjlr@exchange.nordstrom.com"
Subject = "any old subject"
Body = "any old body text"
ErrDescr = " "
Attachment1 = "d:\found.not"
RC = MailObj.SendMail_Send(Sender,Recipient,Subject,Body,ErrDescr,Attachment1) 

Answer:

The basic problem is that Winbatch is not 100% happy with BYREF return parameters. Thus the route via a Binary Buffer is required.

MailObj = ObjectOpen("dllSendMail.dllSendMail")
Sender = "crccdi@exchange.nordstrom.com"
Recipient = "xjlr@exchange.nordstrom.com"
Subject = "any old subject"
Body = "any old body text"
bb=BinaryAlloc(2000)
BinaryOleType(bb, 200+2,0,0,0)
Attachment1 = "d:\found.not"
RC = MailObj.SendMail_Send(Sender,Recipient,Subject,Body,bb,Attachment1) 
ErrDescr=BinaryPeekStr(bb,0,BinaryEodGet(bb))
BinaryFree(bb)