Subclassing [RESOLVED]

[Tool]

Hello everyone.

I have heard quite a bit about subclassing, but never have used it and dont really know what it is.

My belief is that when you want to watch something on another program you need to subclass it in your application to check it for changes, or what not.

Could someone please give me a description of what it is (if I am wrong) and possibly an example of how I would subclass something? I would eventually like to subclass some chat applications like irc (if I was semi-right about subclassing) to flash/open/beep or anything when someone types your name

Any help would be appreciated and thank you

[moeur]

I'm sure that by posting this question you have already searched the forums for your answers.

Subclassing refers to the process of "hooking" into the window procedure for a window (in VB a window is called a form or a control). The Window Procedure is where Windows messages are handled. By intercepting these messages you can change the way the window behaves by discarding the message or changing it.

Another closely related process is called hooking. Hooking puts the intercept point a little further upstream in what is sometimes referred to as the message pump. This is a procedure that takes messages from the message queue and sends them to the Window procedure. There are several types of hooks, in some of them you can discard the message, in others you can change the message and in some you can only monitor the message.

You cannot Subclass a process outside the process of your program, but you can hook it. See my post in the code bank for code written to do this.

A book I would like to recommend on the subject is Subclassing & Hooking with Visual Basic. Check it out.

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[Tool]

Thank you very much on all the information in your post. I do understand the message loop/pump idea. I just made my first window in c++ with a friends help so that is not all too foreign. I have been looking for good books to get (I love learning, but hate books that start too slow). I have a bunch that I cant get past page 100 because it bores me. I have been looking for some good books on API, I will surely get that one soon and hopefully understand how it all works, and how to use it. Thanks again

[RobDog888]

I know you resolved your thread but I just wanted to give you a link to my Sub-Classing example since it will help
you to understand the basics of subclassing in your own application first. Maybe it will help you with the other advanced examples.