Go Premium for a chance to win a PS4. Enter to Win

x
  • Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 1711
  • Last Modified:

C++ Builder:How can I change WndProc to my own?

Before starting my program by Application->Run() method,
I tried to change WndProc to my own by SetClassLong(), but
nothing happend. My own CALLBUCK MyWndProc() did't get
messages. My question is how can I replace address of WndProc in WNDCLASS to my own address for proceeding messages by MyWndProc()? If you can help me, please e-mail
to jcrsch@game-club.com Thank you.
0
alexander031597
Asked:
alexander031597
  • 4
  • 2
  • 2
1 Solution
 
alexander031597Author Commented:
Edited text of question
0
 
chensuCommented:
Are you using MFC?

0
 
chensuCommented:
I am sorry that I clicked on the wrong button. I just wanted to add a comment.
0
VIDEO: THE CONCERTO CLOUD FOR HEALTHCARE

Modern healthcare requires a modern cloud. View this brief video to understand how the Concerto Cloud for Healthcare can help your organization.

 
alexander031597Author Commented:
No, I don't use MFC.
0
 
alexander031597Author Commented:

0
 
LeoVCommented:
If you are working with window of your own class, you probably used function RegisterClass(const WNDCLASS* lpWndCls)to register it.
In this case you simply have to assign ---address--- of your WndProc function to lpWndCls->lpfnWndProc before registring the class.
---
lpWndCls->lpfnWndProc=MyWndProc;
or
lpWndCls->lpfnWndProc=&(MyWndProc());
whatever your compiler will accept.
0
 
alexander031597Author Commented:
Your answer is good for C++ compiler, but we are tolking about C++ Builder compiler. So I didn't use RegisterClass function.
According to Borland's documentation (chapter Handling messages -> Understanding the message-handling system) I should use overriding the handler method. Component Writer's Guide say "You should never need to alter message-dispatch mechanism. All you'll need to do is create message-handling methods." Of course, I know
I should map the methods. But I can't understand why nothing
happened when I changed in WNDCLASS structure address of WndProc
function directly by SetClassLong() function and this address
really was changed, but my WndProc function didn,t receive any messages.

0
 
LeoVCommented:
Tere is easy way: overwrite virtual WindowProc function of your window class.
 The reason you cannot set WindowProc to YourWndProc is that you are not suposed to. when you are working with OWL, you are working with C++ classes, not with Windows classes (I am Sure you know it yourself) so, tere is actually code somewhere, that restres original window procedure and does not let you do stupid things. Or things that Borland considers stupid. If you want to use a hard way and set WindowProc dirrectly, yo have to find a place where C++ class keeps original pointer and change it. I didn't go so far yet.
 By the way, do You speak Russian?
0

Featured Post

Concerto's Cloud Advisory Services

Want to avoid the missteps to gaining all the benefits of the cloud? Learn more about the different assessment options from our Cloud Advisory team.

  • 4
  • 2
  • 2
Tackle projects and never again get stuck behind a technical roadblock.
Join Now