Solved

Event handling in DLL

Posted on 1998-06-29
6
150 Views
Last Modified: 2010-04-04
Maybe I'm just being obtuse:

If I call a function in a DLL that should return an integer and that function uses a process that requires event handling how do I return the result?

For example: my actual function takes some information, massages it, opens a socket connection to a service, writes the data, and receives a response.  That response needs to be returned to the calling application.  However, when I get the response, I'm in the onDataArrival event handler -- far removed from my original function.

How can I return that value?

Any thoughts?

Thanks
- Frank
0
Comment
Question by:FBlair
  • 4
  • 2
6 Comments
 
LVL 5

Expert Comment

by:ronit051397
ID: 1356349
You can send messages between Main Application and DLL and then use the event OnGetMyMessage... or something similar. Is this approach good for you?
If yes, Let me know and I'll post some example.
0
 

Author Comment

by:FBlair
ID: 1356350
Sounds easy enough, but how would that work if the DLL is in Delphi and the calling program is in, say VB?
0
 
LVL 5

Expert Comment

by:ronit051397
ID: 1356351
It doesn't matter, you send messages "to the Handle" of a program, so if you are writing the other program in VB you should see it's documentation on handeling messages.
0
IT, Stop Being Called Into Every Meeting

Highfive is so simple that setting up every meeting room takes just minutes and every employee will be able to start or join a call from any room with ease. Never be called into a meeting just to get it started again. This is how video conferencing should work!

 
LVL 5

Expert Comment

by:ronit051397
ID: 1356352
in the DLL you write somethong like:
sendmessage(Handle which is the Handle of the VB program, WM_MYMESSAGE, here you write the Integer value, 0);

On the VB program you write an event which handles the messages coming to your program.

Or use DDE...
0
 

Author Comment

by:FBlair
ID: 1356353
Cool.  I think I have the idea.  If you'll make it an official answer, I'll take it.

Thanks.
0
 
LVL 5

Accepted Solution

by:
ronit051397 earned 100 total points
ID: 1356354
OK.
0

Featured Post

Why You Should Analyze Threat Actor TTPs

After years of analyzing threat actor behavior, it’s become clear that at any given time there are specific tactics, techniques, and procedures (TTPs) that are particularly prevalent. By analyzing and understanding these TTPs, you can dramatically enhance your security program.

Join & Write a Comment

A lot of questions regard threads in Delphi.   One of the more specific questions is how to show progress of the thread.   Updating a progressbar from inside a thread is a mistake. A solution to this would be to send a synchronized message to the…
Creating an auto free TStringList The TStringList is a basic and frequently used object in Delphi. On many occasions, you may want to create a temporary list, process some items in the list and be done with the list. In such cases, you have to…
Internet Business Fax to Email Made Easy - With eFax Corporate (http://www.enterprise.efax.com), you'll receive a dedicated online fax number, which is used the same way as a typical analog fax number. You'll receive secure faxes in your email, fr…
In this seventh video of the Xpdf series, we discuss and demonstrate the PDFfonts utility, which lists all the fonts used in a PDF file. It does this via a command line interface, making it suitable for use in programs, scripts, batch files — any pl…

759 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

18 Experts available now in Live!

Get 1:1 Help Now